Final Exam Practice Questions MAT 141 – Statistics These practice questions accompany Sullivan, Fundamentals of Statistics, 4th edition. These questions are provided to help you prepare for the final exam. However, please note the following: These practice questions cover only a sample of the material that we covered in this course. You are responsible for all of the material covered in the course, whether or not the material is included in this set of practice questions. The practice questions emphasize certain topics more than others. Do not assume that the final exam will emphasize the same topics. You will have 1 hr. 45 min. to complete the final exam. This set of practice questions is about twice as long as the final exam. While I hope you find these practice questions helpful, it should be just one of several tools you use to help you prepare for the final exam. Other suggestions include: ― Begin studying as early as possible. Don’t try to cram an entire semester’s worth of material the night before the exam. ― Review previous exams and homework assignments and make sure you can rework problems that were not correct the first time. ― Use the chapter Study Guides as a checklist of topics that were covered in this course. ― Work extra problems, especially in areas where you have had difficulty. ― Make sure you understand concepts as well as procedures, i.e., you should understand not only how to do something but why you are doing it. Find a study partner and drill each other on concepts (which are listed in the study guides). If you have difficulty explaining something, you probably need to study it some more. ― If you have questions, please take advantage of your instructor’s office hours and/or the tutoring available in the Individual Learning Center. Read the following and then answer Questions 1 – 3: On the first day of class, an instructor asks his students to supply the following information about themselves: ― Height (in inches) ― Time they woke up that morning ― Number of siblings who live in their household ― Place of birth 1. Which variable can be classified as a “quantitative discrete” variable? (A) Height (B) Wake-up time (C) Number of siblings in household (D) Place of birth (E) None of these [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 2 2. Which variable can be classified as a “qualitative” variable? (A) Height (B) Wake-up time (C) Number of siblings in household (D) Place of birth (E) None of these 3. If the instructor made a list of all the heights, the numbers in that list would be a: (A) Population (B) Sample (C) Variable (D) Data set (E) None of these 4. Which variable has a “nominal” level of measurement? (A) Height (B) Wake-up time (C) Number of siblings in household (D) Place of birth (E) None of these 5. Which variable has an “ordinal” level of measurement? (A) Height (B) Wake-up time (C) Number of siblings in household (D) Place of birth (E) None of these 6. Which variable has an “interval” level of measurement? (A) Height (B) Wake-up time (C) Number of siblings in household (D) Place of birth (E) None of these 7. A study on attitudes about smoking is conducted at a college. All students are divided by class (freshman, sophomore, junior, and senior). Then a simple random sample is selected from each class and interviewed. Which sampling technique was used in the study? (A) Random (C) Systematic [email protected] (B) Stratified (D) Cluster kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 3 8. In a statistical study of a new drug, data are collected from two groups of people – those who received the new drug and those who received a pill with no active ingredients. The people who received the pill with no active ingredients are called: (A) Experimental (or treatment) group (B) Observational group (C) Control group (D) Placebo 9. A health club surveyed 40 randomly selected members and found that the mean weight of those surveyed is 157 pounds. “157 pounds” is an example of a: (A) Sample (C) Parameter (B) Statistic (D) Variable 10. In the previous question, the 40 people who were surveyed are a: (A) Sample (C) Control group (B) Population (D) Treatment group 11. At Widget Manufacturing, the mean salary of all female workers is $35,000 and the mean salary of all male workers is $41,000. Which of the following is true about the mean salary of all workers (male and female combined) at the company? (A) It must be $38,000. (B) It must be larger than the median salary. (C) It must be between $35,000 and $41,000. (D) All of the above. 12. Which of the following measures roughly describes the average location of data points relative to the mean? (A) (B) (C) (D) Median Percentile Standard deviation Mode [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 4 Percent 13. An industrial company researches the mean pH level of the water in a nearby river. For fifty randomly selected water samples the pH level was recorded. The distribution of recorded pH levels was presented in the following relative frequency distribution histogram. Which of the following is appropriate conclusion? 35 25 20 15 10 5 pH levels 0 5.875 6.125 6.375 6.625 6.875 7.125 7.375 7.625 Number of guests (A) [100,110) (B) [110,120) (C) [130,140) (D) [150,160) 40 30 (A) Approximately 86% of the analyzed water samples have pH levels between 6.375 and 7.125. (B) About 5% of the water samples have pH levels below 6.1. (C) The pH levels are uniformly distributed. (D) All of the above (E) None of these 14. Fifty hotel guests were asked how much money they paid for their hotel room last night. The results are shown in the histogram at the right. Which class contains the 80th percentile? 45 100 110 120 130 140 150 160 170 180 190 200 Price of hotel room (dollars) The numbers on the horizontal axis represent lower class limits, e.g., the first class is [100,110), the second class is [110,120), etc. 15. Another name for “Q1” is: (A) 1st percentile (B) 10th percentile (C) 25th percentile (D) Median (E) None of these [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 5 16. A study was performed to analyze the time (in minutes) it takes students to complete an exam. A study was done on 50 randomly selected students. The distribution of times (in minutes) was presented in the following boxplot. Which of the following is an appropriate conclusion? (A) More than half of the students took longer than 40 minutes to complete a test. (B) The mean time to complete a test was longer than 40 minutes. (C) The distribution is skewed-left. (D) All of the above. (E) None of these 17. The manufacturer wants to compare the calling range (in miles) of its 900-MHz cordless telephone to the calling range of its leading competitor. A comparative study was done using two independent samples of 50 telephones from the manufacturer and its competitor. The distributions of the calling ranges from the manufacturer and its leading competitor are presented in the graph. Which of the following is an appropriate conclusion? 0 50 100 time competitor manufacturer 1200 1250 1300 (A) Both distributions are symmetric. calling range (miles) (B) The calling range is longer on average for the manufacturer’s 900-MHz cordless telephones. (C) The amount of variation is approximately the same for both the manufacturer and its leading competitor. (D) All of the above. (E) None of these [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 6 18. In which of the following distributions is the mean greater than the median? (A) (B) (C) (D) Distributions B and C (E) The mean and the median are equal in all three distributions. 19. The pie-chart displays the distribution of the NASA space shuttle operation expenditures (in millions of dollars) for 2001. What is the appropriate conclusion? NASA space shuttle operations Expenditures in 2001 Main Engine (9.8%) Mission/launch operations (29.2%) External Tank ( 13.1%) Solid rocket booster (5.1%) Orbiter and integration ( 27.1%) Reusable solid rocket motor ( 15.7%) (A) More than 50% of the budget was spent on mission/launch operations together with orbiter and integration. (B) The smallest percent of the budget was spend on solid rocket booster. (C) Approximately the same amount of money was spent on the external tank and reusable solid rocket motor. (D) All of the above. (E) None of these [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 7 20. The “z-score” associated with a data point measures (A) The frequency of the data point (B) How far the data point is from the mean (C) A probability (D) The spread of the distribution (E) None of these 21. After grading a Statistics test in a class of 25 students, the instructor calculated the mean, median and standard deviation of the test scores. The student with the highest score found a grading error, which changed her score from 96 to 98. Which of the measures is not impacted by this change? (A) Mean (B) Median (C) Standard deviation (D) All three measures are impacted by the change (E) None of the measures is impacted by the change 22. Which of the following pairs of events are disjoint (mutually exclusive)? (A) A single die is rolled once. Event A: “The result is an odd number” Event B: “The result is a 3” (B) A student is randomly selected. Event A: “The student is taking a mathematics course” Event B: “The student is taking a business course” (C) A single card is drawn from a deck of 52 cards. Event A: “The result is a club” Event B: “The result is a King” (D) A single die is rolled. Event A: “The result is a number greater than 4” Event B: “The result is a number less than 4” (E) None of these [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 8 Use the following table to answer Questions 23 – 26: A blood bank catalogs the types of blood, including positive or negative Rh-factor, given by donors during the last five days. The number of donors who gave each blood is listed in the table below. Rh-factor Rh-positive Rh -negative Totals O 150 30 180 Blood Type A B 135 37 25 12 160 49 Totals AB 13 8 21 335 75 410 23. Find the probability that a randomly selected donor does not have blood type A. (A) 0.3902 (B) 0.6098 (C) 0.3293 (D) 0.0610 24. Find the probability that a randomly selected donor has either blood type AB or Rh-positive factor. (A) 0.8683 (B) 0.9 (C) 0.8366 (D) 0.1317 25. Find the probability that a randomly selected donor has blood type B. (A) 0.7551 (B) 0.8805 (C) 0.0902 (D) 0.1195 26. Find the probability that a randomly selected donor has blood type B and Rh-negative factor? (A) 0.2449 (B) 0.16 (C) 0.2732 (D) 0.0293 27. Which of the following variables is a discrete random variable? (A) The number of siblings of a randomly selected student. (B) The number of people (crew size) on a randomly selected mission by NASA. (C) The number of tellers available to serve customers in a bank between 12 and 1 pm. (D) All of the above (E) None of these 28. Which of the following variables is a continuous random variable? (A) The amount of milk in a “1-gallon” carton (B) The amount of sugar (in pounds) eaten each day in the US. (C) The daily temperature of a patient during a hospital stay (D) All of the above (E) None of these [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 9 Use the following probability distribution to answer Questions 29 – 31 The table shows the probabilities of prior DWI (Driving While Intoxicated) sentences for jail inmates convicted of DWI. (Source: US Department of Justice) Number of prior DWI sentences Probability 0 0.512 1 0.301 2 0.132 3 0.055 29. What is the probability of selecting a jail inmate with at least 2 prior DWI sentences? (A) 0.055 (B) 0.187 (C) 0.945 (D) 0.813 30. What is the probability of selecting a jail inmate with at most 1 prior DWI sentences? (A) 0.488 (B) 0.187 (C) 0.945 (D) 0.813 31. What is the expected number of prior DWI sentences for a randomly selected jail inmate? (A) Between 0 and 1 (C) Between 2 and 3 (B) Between 1 and 2 (D) Between 3 and 4 32. You roll two dice – a red die and a green die. What is the probability of getting doubles (both dice land on the same number)? (A) 1/3 (B) 1/6 (C) 1/18 (D) 1/36 33. Rolling the same two dice, what is the probability of the following event: red die lands on an odd number and green die lands on 5 or 6 (A) 1/3 (B) 1/6 (C) 4/6 (D) 5/6 34. An airline reports that 20% of its passengers on international flights order special meals. If four international passengers are selected at random, what is the probability that all four passengers ordered a special meal? (A) 0.8 (B) 0.2 (C) 0.05 (D) 0.0016 35. A PIN (personal identification number) is a sequence of any four characters from the 26 letters of the alphabet and the digits 0-9, with repetitions allowed. How many such PINs are possible? (A) 1,679,616 (B) 1,413,720 (C) 260 (D) 456,976 36. Continuing with the previous question, how many PINs would be possible if repetitions were not allowed? (A) 1,413,720 [email protected] (B) 358,800 (C) 234 kradermath.jimdo.com (D) 58,905 Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 10 37. Which of the following are true about counting methods? (A) In a combination order does not matter, but different orders result in different permutations. (B) In a permutation, repetition is not allowed, but in a combination repetition is allowed. (C) For groups of r objects chosen from a group of n objects, there are more permutations than there are combinations. (D) Both A and C (E) Both B and C 38. A community college offers 15 different math courses. A researcher wants to mail a survey to students in three of the courses. How many different ways can the three courses be selected? (A) 5 (B) 455 (C) 2730 (D) 3375 39. Valley View Hospital allows its patients to choose from a menu of 3 breakfast entrees, 5 lunch entrees and 8 dinner entrees. How many daily menu choices are there? (A) 16 (B) 560 (C) 3360 (D) 120 40. Which of the following variables is a binomial random variable? (A) A fair coin is tossed until it lands on heads 10 times. X = the total number of tosses. (B) A fair die is rolled 10 times. X = the number of times the die landed on a “3”. (C) A box contains 3 blue marbles, 2 red, and 5 white marbles. Three marbles from the box are selected at random, without replacement. X= the number of red marbles out of the 3 marbles. (D) All of the above. (E) None of these. 41. According to the Daily Racing Form, the probability is about 67% that the favorite in a horse race will finish in the money (first, second, or third place). In the next eight races, what is the probability that the favorite finishes in the money in exactly two races? (A) 0.0162 (B) 0.0003 (C) 0.9997 (D) 0.9838 42. In a recent referendum, 30% of the voters supported a property tax increase to provide additional money for education. If 5 voters are chosen at random, what is the probability that at least one of the voters supported the property tax increase? (A) 0.36 (B) 0.47 [email protected] (C) 0.53 (D) 0.83 kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 11 43. In the year 2000, the periodical Zero Population Growth reported that the US led the fully industrialized world in teen pregnancy rates, with 40% of US females getting pregnant at least once before reaching the age of 20. In a sample of 10 randomly selected 20-year-old females, what is the probability that at least 6 of them have been pregnant at least once before the age of 20? (A) 0.1115 (B) 0.8338 (C) 0.1662 (D) 0.9452 44. As reported by Television Bureau of Advertising, Inc., in Trends in Television, 84.2% of US households have a VCR. If 18 households are randomly selected for observational study, what is the probability that at most 15 households will have a VCR? (A) 0.5581 (B) 0.4419 (C) 0.244 (D) 0.8019 45. Nine percent of men cannot distinguish between the colors red and green. This is the type of color blindness that causes problems with traffic signals. If six unrelated men are randomly selected for a study of traffic signal perception, what is the probability that more than 3 of them have difficulty distinguishing between red and green? (A) 0.0110 (B) 0.9992 (C) 0.0008 (D) 0.0118 46. In a housing study, it was found that 26% of college students live in campus housing (based on data from the Independent Insurance Agents of America). In a sample of 25 randomly selected college students, how many students do you expect will be living in campus housing? (A) Between 2 and 3 (C) Between 6 and 7 (B) Between 4 and 5 (D) Between 18 and 19 47. In a normal distribution, approximately 99.7% of the data points lie within how many standard deviations of the mean? (A) 1 standard deviation (C) 3 standard deviations (B) 2 standard deviations (D) 4 standard deviations 48. The diagram at the right shows three normal distributions. Which of the distributions has the greatest standard deviation? (A) (B) (C) (D) A Distribution A Distribution B Distribution C All three distributions have the same standard deviation B C [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 12 49. An airline knows from experience that the number of suitcases that are lost each week on a certain route is normally distributed with the mean of 15.5 suitcases and a standard deviation of 3.6 suitcases. What is the probability that during a given week the airline will lose between 10 and 20 suitcases on that route? (A) 0.8314 (B) 0.3944 (C) 0.1056 (D) 0.4040 50. Assume that the lengths of pregnancies are normally distributed with a mean of 268 days and a standard deviation of 15 days. What is the probability of a pregnancy lasting at least 300 days? (A) 0.0166 (B) 0.9834 (C) 0.2375 (D) 0.3189 51. Assume that the starting salaries of elementary school teachers in the US are normally distributed with a mean of $31,000 and a standard deviation of $3,000. What percent of US elementary school teachers receive a starting salary of at most $25,000? (A) 2.28% (B) 99.81% (C) 21.13% (D) 98.27% 52. The average price of a certain type of used car is $6500 with a standard deviation of $850. If a used car dealer wants to deal with the middle 75% of the market, what will the dealer’s price range be? (A) $6229 – $6771 (D) $5522 – $7478 (B) $6423 – $6577 (C) $5926 – $7073 53. The total cholesterol of US women ages 50-59 is approximately normally distributed with a mean of 228 milligrams per deciliter of blood and a standard deviation of 43.8 milligrams per deciliter of blood. What is the total cholesterol level exceeded by only 2.5% of women ages 5059? (A) 313.85 (B) 142.15 (C) 155.95 (D) 300.05 54. On a dry surface, the braking distance (in meters) of a Pontiac Grand AM SE can be approximated by a normal distribution with a mean of 45.1 meters and standard deviation of 0.5 meters. What braking distance of a Pontiac Grand AM SE represents the first quartile? (A) 44.98 (B) 44.76 (C) 45.44 (D) 45.23 55. The distribution of actual weights of 8-oz chocolate bars produced by a certain machine is normal with a mean of 8.1 ounces and standard deviation of 0.1 ounces. What is the probability that the mean of 9 such chocolate bars will be less than 8.15 ounces? (A) 0.0668 (B) 0.9332 [email protected] (C) 0.6915 (D) 0.3085 kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 13 56. In a large population of adults, IQ scores are normally distributed with a mean of 112 and standard deviation of 20. What is the probability that the mean IQ of 16 adults will be between 105 and 123? (A) 0.9053 (B) 0.3456 (C) 0.0669 (D) 0.8159 57. An automobile insurer has found that repair claims have a mean of $920 and a standard deviation of $870. What is the probability that the mean of 100 claims is larger than $1,000? (A) 0.9200 (B) 0.8212 (C) 0.0800 (D) 0.1788 58. If the heights of US adult women are normally distributed with a mean of 65.5 inches, then which of the following is least likely to occur? (A) The height of a randomly selected woman is more than 72 inches. (B) The mean height from a random sample of 10 women is more than 72 inches. (C) The mean height from a random sample of 40 women is more than 72 inches. (D) All three events are equally likely. 59. Which of the following is true about the standard normal distribution? (A) It is bell-shaped and symmetric around the mean (B) The mean, median, and mode are equal. (C) The area underneath the total curve is 1. (D) All of the above. (E) None of these 60. Which of the following is true about a Student’s t-distribution? (A) It is a bell-shaped and symmetric distribution around the mean. (B) There are infinitely many t-distributions. (C) There is more variation in a t-distribution than in the standard normal distribution. (D) All of the above (E) None of these 61. Which of the following is true about confidence interval estimates? (A) The higher the confidence level, the larger the margin of error. (B) The larger the sample size, the smaller the margin of error. (C) The higher the confidence level, the wider the confidence interval estimate. (D) All of the above. (E) None of these [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 14 62. Nielsen Media Research wants to estimate the mean amount of time (in minutes) that full-time college students spend watching television each weekday. Find the minimum sample size required to estimate that mean within 15 minutes with 95% confidence. From a pilot study the standard deviation is estimated to be 112.2 minutes. (A) 15 (B) 215 (C) 152 (D) 110 63. A pollster reports that 32% of US voters approve of the president’s job performance “plus or minus 4%.” In this poll, “4%” is called the: (A) Confidence level (C) Significance level (B) Margin of error (D) Standard deviation 64. A study was conducted to estimate hospital costs for accident victims who wore seat belts. The distribution of hospital costs is approximately normal. Sixteen randomly selected cases have been selected for a study, and the mean hospital cost for the sample of 16 cases was $9000 with a standard deviation of $2000. Construct a 99% confidence interval estimate for the mean hospital cost for all accident victims who wore seat belts. (A) ($7720, $10,280) (C) ($7526.60, $10,473.00) (B) ($7539.50, $10,460.50) (D) ($8020, $9980) 65. A sociologist wants to determine the current percentage of US households using e-mail. Determine the minimum sample size required in order to be 95% confident that her estimate is within 4% of the true proportion of all US households using e-mail. Suppose a pilot study indicated that 65% of surveyed households use e-mail. (A) 547 (B) 115 (C) 423 (D) 601 66. In a Gallup poll, 1025 randomly selected adults were surveyed, and 298 of them said that they used the Internet for shopping at least a few times a year. Find a 95% confidence interval estimate of the proportion of adults who use the Internet for shopping at least a few times a year. (A) (26.01%, 32.13%) (C) (23.51%, 34.63%) (B) (26.29%, 31.85%) (D) (17.95%, 40.19%) 67. In a hypothesis test, which of the following is true about the p-value? (A) Assuming the null hypothesis is true, the p-value is the probability of obtaining a sample statistic with a value as extreme or more extreme than the one determined from the sampled data. (B) The p-value is the maximum allowed probability of rejecting the null hypothesis when it is true. (C) The larger the p-value, the more evidence you have to reject the null hypothesis. (D) All of the above. (E) None of these. [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 15 68. Which of the following is true about hypothesis testing? (A) The alternative hypothesis is always a statement of inequality. (B) The null hypothesis is always a statement of equality. (C) Both hypotheses are stated in terms of a population parameter. (D) All of the above. (E) None of these. 69. In a random sample of 100 American males between the ages of 18 and 21 the average height was 6.1 ft with a standard deviation of 0.21 ft. Specify the hypotheses used to test the claim that the mean height of American males between 18 and 21 years of age is now over 6 ft. (A) H0: μ=6 H1: μ≠6 (B) H0: μ=6 (C) H0: μ=6 H1: μ>6 (D) H0: μ=6.1 H1: μ<6 H1: μ>6.1 70. The state police commander reported that 35% of drivers on a busy freeway are driving at least 10 mph over the speed limit. In a sample of 120 cars, a highway patrol officer with a radar gun found 48 drivers (i.e., 40%) who exceeded the speed limit by 10 mph or more. The patrol officer claims that the police commander is not correct. State the hypotheses used to test the patrol officer’s claim. (A) H0: p=0.40 H1: p≠0.40 (B) H0: μ=10 (C) H0: p=0.35 H1: p>0.35 (D) H0: p=0.35 H1: μ<10 H1: p0.35 71. A simple random sample of 25 postal service employees found that the average time these employees had worked for the postal service was 7 years with a standard deviation of 2 years. The distribution of the time the population of employees have worked for the postal service is approximately normal. Find the p-value used to determine whether there is enough evidence to support the claim that the average time an employee worked for the postal service has decreased from 7.5 years (which was the average about 10 years ago)? (A) 0.11 (B) 0.22 (C) 0.44 (D) 0.76 72. An auto repair shop reports that 75% of its jobs are completed ahead of schedule. An audit of 104 jobs found that 73 were completed ahead of schedule. Find the p-value used to test the claim that fewer than 75% of jobs were completed ahead of schedule. (A) 0.13 (B) 0.26 (C) 0.74 (D) 1.13 73. In a hypothesis test, there is still a possibility that the null hypothesis is true even if it is rejected The probability of rejecting the null hypothesis when it is true is called the: (A) (B) (C) (D) p-value z-value Significance level (α) Margin of error [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 16 74. According to corporate headquarters, customers at Hempel’s Department Store have a mean household income of $91,600. The manager of the store in Northwoods Mall claims that her customers have higher incomes. She surveys 100 randomly selected customers and finds that their mean income is $96,321. She uses that statistic along with the sample standard deviation to compute a p-value and test her claim. If p-value < α, how should she state the results? (A) There is enough evidence to support the store manager’s claim that the mean household income of Northwoods Mall customers is greater than $91,600. (B) There is not enough evidence to support the store manager’s claim that the mean household income of Northwoods Mall customers is greater than $91,600. (C) There is enough evidence to support corporate headquarters’ claim that the mean household income of Hempel’s customers is $91,600. (D) There is enough evidence to support the store manager’s claim that the mean household income of Northwoods Mall customers is $96,321. 75. The American Automobile Association (AAA) claims that 54% of fatal car/truck accidents are caused by driver error. A researcher studied 30 randomly selected accidents and found that 14 were caused by driver error, which leads the researcher to dispute the AAA’s claim. The researcher performs a hypothesis test. If p-value > α, how should the researcher summarize her results? (A) There is enough evidence to dispute the AAA’s claim that 54% of fatal car/truck accidents are caused by driver error. (B) There is not enough evidence to dispute the AAA’s claim that 54% of fatal/car truck accidents are caused by driver error. (C) There is enough evidence to support the AAA’s claim that 54% of fatal car/truck accidents are caused by driver error. (D) There is not enough evidence to support the AAA’s claim that 54% of fatal car/truck accidents are caused by driver error. 76. Newton Center and Newton Junction are two adjacent towns with very similar demographics. For years, Newton Realty had told its clients that real estate prices in the two towns were the same. However, a real estate agent at a competing firm sampled the price of real estate in each town and got the following results: Newton Center Newton Junction n1 = 35 n 2 = 40 X 1 = $63,255 s1 = $5602 X 2 = $59,102 s 2 = $4731 The competing agent used this data to test Newton Realty’s claim. If p-value < α, how should the competing agent summarize her results? (A) There is enough evidence to support the claim that the mean price in Newton Center is higher than the mean price in Newton Junction. (B) There is enough evidence to support the claim that the mean price in Newton Center is the same as the mean price in Newton Junction. (C) There is enough evidence to support the claim that the mean price in Newton Center is different than the mean price in Newton Junction. (D) There is enough evidence to support the claim that the difference between the mean prices is $4153. [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 17 77. Increasing numbers of businesses are offering child-care to their employees. In fact, a local Chamber of Commerce says that 40% of its members offer child care. However, in a sample of 50 businesses, you find only 15 who offered child care. At α=0.05, test the claim that the actual number of businesses offering child care is less than 40%. What is the appropriate conclusion? (A) Reject the null hypothesis. There is not enough evidence to support the claim that less than 40% of businesses offer child care. (B) Reject the null hypothesis. There is enough evidence to support the claim that less than 40% of businesses offer child care. (C) Do not reject the null hypothesis. There is enough evidence to support the claim that 40% of businesses offer child care. (D) Do not reject the null hypothesis. There is not enough evidence to support the claim that less than 40% of businesses offer child care. 78. A researcher wants to test the effect of a calcium supplement on the taste of yogurt. The taste was measured on the scales 1 to 10, 1 being “very unpleasant” and 10 being “very pleasant”. A mean rating for 16 randomly selected adults who tasted yogurt containing the extra calcium was 6.5 with a standard deviation of 1.5. An independent random sample of 14 adults who tasted yogurt without the added calcium gave a mean rating of 7 with a standard deviation of 2. The distribution of ratings for taste with and without the added calcium are approximately normally distributed. At the 10% significance level, do the data provide sufficient evidence to support the claim that the mean rating of the taste is significantly lower for the yogurt with the added calcium? What is the appropriate p-value? p value 0.01 (C) 0.05 p value 0.1 (E) p value 0.25 (A) 0.01 p value 0.05 (D) 0.1 p value 0.25 (B) 79. Is the mean weight of regular Coke less than the mean weight of regular Pepsi? To test this claim, two independent samples of cans of each brand were selected for testing. The sample statistics are summarized in a table below. The distributions of weights of regular Coke and regular Pepsi are approximately normal. At the 5% significance level, what is the appropriate conclusion? Regular Coke Regular Pepsi n1 = 15 x1 = 0.8168 s1 = 0.0075 n 2 = 10 x 2 = 0.8241 s 2 = 0.0057 (A) Reject the null hypothesis. Data do not support the claim that the mean weight of regular Coke is less than the mean weight of regular Pepsi. (B) Reject the null hypothesis. Data support the claim that the mean weight of regular Coke is less than the mean weight of regular Pepsi. (C) Do not reject the null hypothesis. Data do not support the claim that the mean weight of regular Coke is less than the mean weight of regular Pepsi. (D) Do not reject the null hypothesis. Data support the claim that the mean weight of regular Coke is less than the mean weight of regular Pepsi. [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 18 80. Which of the following situations describe two dependent samples. (A) A teacher compares the pre-test and post-test scores of the same set of students. (B) A teacher compares the scores of students using a computer-based method of instruction with the scores of other students using a traditional method of instruction. (C) A teacher compares the scores of students in her class on a standardized test with the national average score. (D) All of the above (E) None of these 3300 Acres harvested 81. The scatter plot represents the relationship between the number of acres of rice planted (in thousands) and number of acres of rice harvested (in thousands) in the United States for eight years. Which of the following is an appropriate conclusion? 3200 3100 3000 2900 (A) The linear correlation coefficient is closer to 1 than to 0. 2800 (B) There is very strong positive linear relationship between the number of acres 2800 2900 3000 3100 3200 of rice planted and the number of acres of Acres planted rice harvested. (C) As the number of acres of rice planted increases, the number of acres of rice harvested tends to increase as well. (D) All of the above. (E) None of these 3300 82. In a linear regression analysis, a correlation coefficient of 0.9 with a high level of significance would mean: (A) (B) (C) (D) (E) There is a strong linear correlation between the two variables. There is little or no correlation between the two variables. As the independent variable decreases, the dependent variable also tends to decrease. Both A and C. None of these 83. A linear regression analysis has shown that there is a strong positive linear correlation between the amount of sugar consumed and the total number of childhood cavities. Which of the following can not be said based on this regression analysis alone? (A) (B) (C) (D) (E) The correlation coefficient is close to 1. As sugar consumption increases, so does the number of cavities. Increased sugar consumption causes cavities. Sugar consumption can be used to predict the number of cavities. None of these (i.e., all four statements are true). [email protected] kradermath.jimdo.com Iss 5.0 3400 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 19 84. Which of the following sampling methods does not require a list of individuals in the population? (A) (B) (C) (D) Simple random sampling Systematic sampling Stratified sampling Cluster sampling 85. A drug company wanted to test a new depression medication. The researchers found 600 adults aged 25-35 and randomly assigned them to two groups. The first group received the new drug, while the second received a placebo. After one month of treatment, the percentage of each group whose depression symptoms decreased was recorded and compared. What is the response variable in this experiment? (A) (B) (C) (D) The percentage of participants with decreased depression symptoms The type of drug (medication or placebo) The ages of the adults who participated in the study The treatment time (one month) 86. Identify the experimental units in the study described in the previous question. (A) (B) (C) (D) The 600 adults who participated in the study The amount of drug (or placebo) that each adult received. The percentage of participants with decreased depression symptoms The ages of the adults who participated in the study 87. Between 1996 and 2006, the percentage of students who graduated from an adult education program rose steadily from 83.2% to 84.1%. A time-series graph is drawn to depict the results. Which of the following techniques will exaggerate the improvement in graduation rate? (A) (B) (C) (D) Use lots of different colors in the graph. Do not label the years on the x-axis. Truncate the y-axis. All of the above. 88. An administrative assistant orders four types of pens from an office supply company. 20% of the pens cost $1.29 each, 10% of the pens cost $1.69 each, 25% of the pens cost $1.79 each and 45% of the pens cost $0.99 each. Determine the mean cost per pen. (A) $0.33 (B) $1.32 [email protected] (C) $1.44 (D) $1.49 kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 20 89. A random sample of sale prices of homes yielded the following summary information: Q1: $81,000 Median: $138,000 Q3: $169,000 Which of the following sale prices would be considered outliers? (A) (B) (C) (D) Any home that costs more than $169,000 Any home that costs more than $257,000 Any home that costs more than $270,000 Any home that costs more than $301,000 90. If nothing is known about the shape of a distribution, what percentage of observations fall within three standard deviations of the mean? (A) (B) (C) (D) At least 89% At most 11% Approximately 95% Approximately 99.7% [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 21 Section Numbers If you are stuck, review the appropriate section in the textbook before looking up the answer. (Solutions are on the following page.) No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Sec.* 1.1 1.1 1.1 1.1 1.1 1.1 1.4 1.6 1.1 1.1 3.1 3.2 2.2 2.2, 3.4 3.4 3.5 3.5 3.1 2.1 3.4 3.1, 3.2 5.2 5.2 5.2 5.1 5.2 6.1 6.1 6.1 6.1 No. 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Sec.* 6.1 5.1, 5.3 5.3 5.3, 6.2 5.5 5.5 5.5 5.5 5.5 6.2 6.2 6.2 6.2 6.2 6.2 6.2 3.2 3.2, 7.1 7.2 7.2 7.2 7.2 7.2 7.2 8.1 8.1 8.1 8.1 7.2 9.2 No. 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 Sec.* 9.1 9.2 9.1 9.2 9.1 9.1 10.1 10.1 10.3 10.1 10.3 10.2 10.1 10.3 10.2 11.3 10.2 11.3 11.3 11.2 4.1 4.1 4.1 1.3, 1.4 1.6 1.6 2.3 3.3, 6.1 3.4 3.2 * Section numbers refer to: Sullivan, Fundamentals of Statistics, 4th edition. [email protected] kradermath.jimdo.com Iss 5.0 Final Exam Practice Questions MAT 141 – Statistics G. H. Krader, Instructor Page 22 Solutions If you are stuck, review the appropriate section in the textbook before looking up the answer. (Section numbers without solutions are on the previous page.) No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Sec.* 1.1 1.1 1.1 1.1 1.1 1.1 1.4 1.6 1.1 1.1 3.1 3.2 2.2 2.2, 3.4 3.4 3.5 3.5 3.1 2.1 3.4 3.1, 3.2 5.2 5.2 5.2 5.1 5.2 6.1 6.1 6.1 6.1 Ans. C D D D E B B C B A C C A C C B D B D B B D B C D D D D B D No. 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Sec.* 6.1 5.1, 5.3 5.3 5.3, 6.2 5.5 5.5 5.5 5.5 5.5 6.2 6.2 6.2 6.2 6.2 6.2 6.2 3.2 3.2, 7.1 7.2 7.2 7.2 7.2 7.2 7.2 8.1 8.1 8.1 8.1 7.2 9.2 Ans. A B B D A A D B D B A D C A C C C C A A A D A B B A D C D D No. 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 Sec.* 9.1 9.2 9.1 9.2 9.1 9.1 10.1 10.1 10.3 10.1 10.3 10.2 10.1 10.3 10.2 11.3 10.2 11.3 11.3 11.2 4.1 4.1 4.1 1.3, 1.4 1.6 1.6 2.3 3.3, 6.1 3.4 3.2 Ans. D B B C A B A D C D A A A A B C D D B A D A C B A A C B D A * Section numbers refer to: Sullivan, Fundamentals of Statistics, 4th edition. [email protected] kradermath.jimdo.com Iss 5.0
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