Business Statistics MGT 233, Spring 2015 Homework #3 This homework assignment is due at the beginning of class on April 3, 2015. Instructions: Download the MGT 233 Homework 3 Excel Data.xlsx from the MGT 233 website. Use the appropriate table to create the Excel Descriptive statistics. You must print the output of the descriptive statistics as part of your homework. Answer all parts clearly with proper probability notation and interpretation. Problem 1 Bookit.com—Bookit.com is an online travel company determined and dedicated to becoming the leader in providing travelers with the most intuitive online booking experience full of relevant information, helpful guides and travel tips. Below is a list of prices for spring break hotel rates. The rate listed below is a nightly rate. Assume that prices are normally distributed: Location Hotel Rate Panama City -Seahaven 174 Panama City -Palms Resort 189 Panama City -Beach Resort 256 Cancun -Barcelo Costa 106 Cancun - Oasis 115 Cancun -Hyatt Regency 91 Daytona Beach -Plaza 106 Daytona Beach -Mayan Inn 151 Daytona Beach -La Playa Resort 84 New Orleans -Wyndham Riverfront 379 New Orleans -Ramada Plaza 255 New Orleans -Maison Dupuy Hotel 324 Miami -Royal Palm Hotel 430 Miami -Carlton Hotel 299 Miami -Whitelaw Hotel 369 Fort Lauderdale -Beach Resort 170 Fort Lauderdale -Sea Club Resort 205 Fort Lauderdale -Hollywood Beach Resort 155 Print the descriptive statistics in Excel and use the information to complete this problem. a) Compute and interpret the 90% confidence level for the average price of a night stay at a hotel during spring break. Interpret the results. b) Compute and interpret the 95% confidence level for the average price of a night stay at a hotel during spring break. Interpret the results. c) Compute and interpret the 99% confidence level for the average price of a night stay at a hotel during spring break. Interpret the results. Problem 2 ESPN.com—The average age of starting quarterbacks has been falling the past two years thanks to good, young passers such as Matt Ryan, Joe Flacco, Sam Bradford, Josh Freeman and others. In 2009 and 2010, the average age of starters was 28.3, down from 29.1 in 2008. Below is a random list of some of the 2011 quarterbacks in the NFL. Name Age Name Age Name Age Name Age Kaepernick, Colin 24 Orton, Kyle 29 O'Connell, Kevin 26 Grossman, Rex 31 Smith, Alex 27 Palko, Tyler 28 Sanchez, Mark 25 Brees, Drew 33 Tolzien, Scott 24 Stanzi, Ricky 24 Hill, Shaun 32 Canfield, Sean 25 Cutler, Jay 28 Collins, Kerry 39 Stafford, Matthew 24 Daniel, Chase 25 Enderle, Nathan 24 Manning, Peyton 35 Stanton, Drew 27 Jackson, Tarvaris 28 Hanie, Caleb 26 Orlovsky, Dan 28 Flynn, Matt 26 Lee, Zac 24 McCown, Josh 32 Painter, Curtis 26 Harrell, Graham 26 Portis, Josh 24 Dalton, Andy 24 Greisen, Chris 35 Hill, Nick 26 Whitehurst, Charlie 29 Gradkowski, Bruce 29 McGee, Stephen 25 Rodgers, Aaron 28 Batch, Charlie 37 Robinson, Zac 25 Romo, Tony 31 Anderson, Derek 28 Dixon, Dennis 27 Fitzpatrick, Ryan 29 Devlin, Pat 23 Clausen, Jimmy 24 Johnson, Jerrod 23 Thigpen, Tyler 27 Henne, Chad 26 Newton, Cam 22 Leftwich, Byron 32 Lewis, Thaddeus 24 Losman, J.P. 30 Brady, Tom 34 Roethlisberger, Ben 30 McCoy, Colt 25 Moore, Matt 27 Hartline, Mike 23 Smith, Troy 27 Wallace, Seneca 31 Edwards, Trent 28 Hoyer, Brian 26 Delhomme, Jake 37 Quinn, Brady 27 Kafka, Mike 24 Mallett, Ryan 23 Garcia, Jeff 42 Tebow, Tim 24 Vick, Michael 31 Boller, Kyle 30 Leinart, Matt 28 Weber, Adam 24 Young, Vince 28 Bomar, Rhett 26 Schaub, Matt 30 Carpenter, Rudy 25 Redman, Chris 34 Campbell, Jason 30 Yates, T.J. 24 Freeman, Josh 24 Ryan, Matt 26 Palmer, Carson 32 Hasselbeck, Matt 36 Johnson, Josh 25 Wilson, John Parker 26 Pryor, Terrelle 22 Locker, Jake 23 Ratliff, Brett 26 Carr, David 32 Bradford, Sam 24 Smith, Rusty 25 Bartel, Richard 29 Manning, Eli 31 Brandstater, Tom 27 Bethel-Thompson, McLeod 23 Hall, Max 26 Perrilloux, Ryan 25 Clemens, Kellen 28 Ponder, Christian 24 Kolb, Kevin 27 Gabbert, Blaine 22 Feeley, A.J. 34 Rosenfels, Sage 34 Skelton, John 23 LeFevour, Dan 24 Flacco, Joe 27 Webb, Joe 25 Rivers, Philip 30 McCown, Luke 30 Taylor, Tyrod 22 Volek, Billy 35 Brunell, Mark 41 Beck, John 30 Cassel, Matt 29 McElroy, Greg 23 Crompton, Jonathan 24 Print the descriptive statistics in Excel and use the information to complete this problem. a) With 95% confidence interval, what is the margin of error? b) What is the 95% confidence interval estimate for the mean age of NFL quarterbacks? Interpret your results. c) What is the 99% confidence interval estimate for the mean age of NFL quarterbacks? Interpret your results. Problem 3 Teamrankings.com— Looking at MLB teams, the average number of team runs per games varies for each team. During the 2012 season, the Texas Rangers lead the league with 4.96 per game followed by the NY Yankees with 4.83. Below is a table random sample of some MLB teams “runs per game”. Assume that the average team runs per game is normally distributed. Team 2012 Philadelphia 4.22 Washington 4.47 Chi Cubs 3.78 Colorado 4.68 Cincinnati 4.14 Toronto 4.42 Pittsburgh 4.02 LA Dodgers 3.93 San Diego 4.02 Arizona 4.53 Texas 4.96 Kansas City 4.17 Detroit 4.40 Boston 4.53 Answer the following questions using calculations by hand (without using Excel). Show the equations and summations need for the calculations. Round all work to three decimal points. a) Compute the standard deviation for the mean runs per game. b) At 99% confidence, what is the margin of error? c) What is the 99% confidence interval for the average runs per game for MLB teams? Interpret the results. Problem 4 iFly.com-- The Transportation Security Administration (TSA) urges all travelers to arrive at the airport well in advance of scheduled flight departures and has provided security checkpoint wait time information as a guide to assist in travel planning. You must also check airlines for ticket counter wait times as well as possible changes to flight schedules. According to historical averages reported by the TSA, at the Omaha Eppley Airfield Airport (OMA), security wait times vary depending on the time of your flight. At 6 AM the average wait time for concourse A is 9.5 minutes while the maximum wait reported is 17 minutes. The population standard deviation is 2.33 minutes. At 6 AM the average wait time for concourse B is 7 minutes while the maximum wait reported is 11 minutes. The population standard deviation is 1.87 minutes. Assuming 80% confidence, what is the sample size that TSA should use to obtain a margin of error of 30 seconds for concourse A? b) Assuming 90% confidence, what is the sample size that TSA should use to obtain a margin of error of 15 seconds concourse B? a) Problem 5 RIP Rating.com--The average NBA player at the start of the 2010-11 season was 26.77 years old and had 4.84 years of NBA experience. Player turnover in the NBA is fast and furious, and you need only look at the roster of your favorite NBA team and compare it to last year to understand this fact. Only exceptional talent lasts in the NBA for any length of time. Shaquille O'Neal of the Boston Celtics was the elder statesman of the NBA this season. Looking at the Boston Celtics roaster the ages of the players vary. Below is the 2010-11 roster for the Boston Celtics. Assume that number of years the players and coach have been in the NBA are normally distributed: Years in PLAYER the NBA Ray Allen 16 Carlos Arroyo 10 Avery Bradley 2 Glen Davis 5 Kevin Garnett 17 Jeff Green 5 JaJuan Johnson 1 Nenad Krstic 8 E'Twaun Moore 1 Troy Murphy 11 Jermaine O'Neal 16 Aleksandar Pavlovic 9 Paul Pierce 14 Rajon Rondo 6 Von Wafer 7 Delonte West 8 Doc Rivers 5 Answer the following questions using Excel descriptive statistics. a) At 80% confidence, what is the margin of error? b) What is the 80% confidence interval for the estimated number of years played in the NBA by a Celtic player? Interpret the results. Problem 6 FOXNEWS.COM, March 11, 2013 NY judge halts Bloomberg ban on large sugary drinks A New York judge is forcing the Bloomberg administration to take a big gulp -- striking down its groundbreaking and controversial limit on the size of sugary drinks in New York City shortly before it was set to take effect. Manhattan state Supreme Court Justice Milton Tingling wrote in his opinion that the rules are "arbitrary and capricious," applying to only certain beverages and only certain stores. "The loopholes in this rule effectively defeat the stated purpose of this rule," he wrote, complaining of "uneven enforcement even within a particular City block, much less the City as a whole." New York City Mayor Michael Bloomberg plans to appeal, his office said on Twitter shortly after the ruling. "We believe (the city) has the legal authority and responsibility to tackle causes of the obesity epidemic, which kills 5,000 NYers a year," his office said, voicing confidence that the measure would be upheld. But Tingling said the city's Board of Health went beyond its authority, and effectively would be "limited by its own imagination" if left unchecked. "The portion cap rule, if upheld, would create an administrative Leviathan and violate the separation of powers doctrine," by straying into territory that should belong to the elected City Council, not the board appointed by Mayor Michael Bloomberg, Tingling wrote. That, he wrote, "has the potential to be more troubling than sweetened beverages. A survey was performed recently by the organization the SPUNK (Student Perspectives at UNK). It surveyed students that were informed and had an opinion whether the judge was correct in removing the limit on the size of sugary drinks in New York City. SPUNK as these students, “Do you believe the judge was correct in removing the limit on the size of sugary drinks in New York City?” Of the 124 informed students that were surveyed and had an opinion, 93 said yes, 31 said no. a) Construct and interpret an 80% confidence interval for the proportion of informed UNK students that believe the judge was correct in removing the limit on the size of sugary drinks in New York City. b) Construct and interpret a 99% confidence interval for the proportion of informed UNK students believe the judge was correct in removing the limit on the size of sugary drinks in New York City. Problem 7 A UNK education is excellent preparation for a successful career, and nowwhere is this more evident than at the annual Career Fair when employers from across the state gather together at the Health and Sports Center to meet, greet and recruit UNK graduate. The Organizer of UNK Career fair took a sample of 60 UNK graduates to check whether they were planning to attend the Career Fair, Half of the students indicated they plan to attend this event. With 80% confidence, the organizer claims that the survey has a margin of error of plus or minus 8.2 percentage points. a) Was the organizer of the Career Fair accurate in reporting a margin of error of 8.2 Percent? Show work by caring the answer to 4 decimal places. b) What sample size is needed for a margin of error of 5 percent with 90 percent confident? c) What sample size is needed for a margin of error of 3 percent with 95 percent confident? d) What sample size is needed for a margin of error of 1 percent with 98 percent confident? Problem 8 Businessweek.com--How did the U.S. become the world's largest economy? A key part of the answer is education. Some 85% of adult Americans have at least a high school degree today, up from just 25% in 1940. Similarly, 28% have a college degree, a fivefold gain over this period. Today's U.S. workforce is the most educated in the world. The above information was found in 2005. You are asked to complete a survey to obtain more current information. a) What sample size would you want to use to estimate the current proportion of individuals who now have a high school degree with a 2% margin of error? Use a 99% confidence level. b) What sample size would you want to use to estimate the current proportion of individuals who now have a college degree with a 5% margin of error? Use a 95% confidence level. Problem 9 Usaswimming.org—The 2012 U.S. Olympic Team Trials Swimming will return June 25-July 2 to Omaha, Nebraska, as one of the fastest, exciting, suspenseful and pressure-filled competitions held in the United States every four years. Check back often for updates as we draw closer to naming the team that will represent the United States in the pool at the London Olympic Games. Looking back at the 2012 Olympic Team Trials, swimmers swam in qualifying heats, semi-final heats, and finals event. Sixteen swimmers made it to the semi-finals and eight swimmers competed in the finals in order to make the USA Olympic team. A random sample of the top swimmers from the first round of heats was taken. A sample of 50 men’s 100m freestyle swimmers shows an average time of 49.68 seconds and a standard deviation of 0.73 seconds. While a sample of 47 men’s 100m butterfly swimmers shows an average time of 53.69 seconds and a standard deviation of 0.76 seconds. a) What is the point estimate of the difference between the mean 100m butterfly times and the mean 100m freestyle times? b) Is the 90% confidence interval for the difference between the average 100m butterfly and 100m freestyle times? Interpret the results. c) Suppose, you want to estimate the average Women’s 100m butterfly time with a new survey. Historically, the standard deviation of times for the Women’s 100m butterfly is about the same as the Men’s 100m butterfly. If you want a 95% confidence and a margin of error within 0.20 seconds, what sample size do you need? Problem 10 Yahoo! Finance (March 4, 2013)--Microsoft Corporation will launch the latest version of its tablet Surface, Surface RT with Windows RT in Japan, Mexico, New Zealand, Russia, Singapore and Taiwan. Further, it will launch its Surface Pro with Windows 8 Pro in Australia, China, France, Germany, Hong Kong, New Zealand and the United Kingdom in March. Microsoft is very bullish about its tablet and is rapidly strengthening its global retail presence. Microsoft is a late entrant into the tablet market and beating the competition at this point will be an uphill task. Other successful tablets such as Apple’s iPads, Google’s Nexus 7, Samsung’s Galaxy tablets and Amazon’s Kindle Fire already have a strong presence in the market. Suppose a follow up survey was performed to compare Nebraska consumers to New York consumers. Out of the 112 Nebraskans surveyed, 84 said they would pick the Surface RT over the iPad. Likewise, 130 individuals from New York were surveyed with 78 preferring the Surface RT. a) Compute the 95% confidence interval for the difference between the proportions of individuals from Nebraska verse New York that would choose the Surface RT over the iPad. Interpret your results.
© Copyright 2024