$15.00
Add to Cart
Ashford BUS308 Week 3 Chapter 11 Assignment
Question 1Stable cost reporting in amanufacturing setting is typically a sign that operations are running smoothly.The accounting department at Rockwell Collins, an avionics manufacturer,analyzes the variance of the weekly costs reported by two of its production departments.A sample of cost reports for each of the two departments shows cost variancesof and , respectively. Is this sample sufficient to conclude that the twoproduction departments differ in terms of unit cost variance? Use (todecimals).
Question 2The competitive advantage of somesmall American factories such as In Tolerance Contract Manufacturing lies intheir ability to produce parts with very narrow requirements, or tolerances,that are typical in the aerospace industry. Consider a product withspecifications that call for a maximum variance in the lengths of the parts of. Suppose the sample variance for parts turns out to be . Use , to test whetherthe population variance specification is being violated. : Test statistic = (to2 decimals, if required)The -value is . Use Table 11.1.
Question 3In its Auto Reliability Survey, Consumer Reports asked subscribersto report their maintenance and repair costs. Most individuals are aware of thefact that the average annual repair cost for an automobile depends on the ageof the automobile. A researcher is interested in finding out whether thevariance of the annual repair costs also increases with the age of theautomobile. A sample of automobiles years old showed a sample standarddeviation for annual repair costs of and a sample of automobiles years oldshowed a sample standard deviation for annual repair costs of .a. State the null and alternative versions of the research hypothesisthat the variance in annual repair costs is larger for the older automobiles.Let year old automobiles be represented by population .b. At a level of significance, what is your conclusion? Calculate the value of the test statistic (to decimals).The -value is . Use Table 4 of Appendix B.that year old automobiles have a larger variance in annual repair costscompared to year old automobiles.
Question 4The variance in a production process is an important measure of the qualityof the process. A large variance often signals an opportunity for improvementin the process by finding ways to reduce the process variance. Jelly BellyCandy Company is testing two machines that use different technologies to fillthree pound bags of jelly beans. The file Bags contains a sample ofdata on the weights of bags (in pounds) filled by each machine.Conduct astatistical test to determine whether there is a significant difference betweenthe variances in the bag weights for the two machines. Use a level ofsignificance. What is your conclusion? Which machine, if either, provides thegreater opportunity for quality improvements? Click on the datafile logo toreference the data. (todecimals)(todecimals)(todecimals) Question 5Battery life is an important issuefor many smartphone owners. Public health studies have examined"low-battery anxiety" and acute anxiety called "nomophobia"that results when a smartphone user's phone battery charge runs low and thendies (Wall Street Journal, May , ). Battery life between charges for theSamsung Galaxy S9 averages hours when the primary use is talk time and hourswhen the primary use is Internet applications. Because the mean hours for talktime usage is greater than the mean hours for Internet usage, the question wasraised as to whether the variance in hours of usage is also greater when theprimary use is talk time. Sample data showing battery life between charges forthe two applications follows. Click on the datafile logo to reference the data. Primary Use: Talking 35.8 22.2 24.0 32.6 18.5 42.5 28.0 23.8 30.0 22.8 20.3 35.5 Primary Use: Internet 14.0 12.5 16.4 11.9 9.9 3.1 5.4 11.0 15.2 4.0 4.7 a. Formulate hypotheses about the two population variances thatcan be used to determine whether the population variance in battery life isgreater for the talk time application. Consider the talk time use as populationand Internet use as population .
b.What are the standard deviations of battery life for the two samples (todecimals)? c.Conduct the hypothesis test and compute the -value.p-value = (todecimals)Using a level of significance, whatis your conclusion?. We that the population variance inbattery hours of use for the talk time application is larger than thepopulation variance in battery hours of use for the Internet application.
Question 6According to the Corporate TravelIndex compiled by Business Travel News, the average daily cost forbusiness travel in the United States rose to per day (Executive Travel website).The file Travel contains sample data for an analogous study on theestimated daily living costs for an executive traveling to variousinternational cities. The estimates include a single room at a four-star hotel,beverages, breakfast, taxi fares, and incidental costs. Click on the datafilelogo to reference the data. City Daily Living Cost ($) City Daily Living Cost ($) Bangkok 242.87 Mexico City 212.00 Bogota 260.93 Milan 284.08 Cairo 194.19 Mumbai 139.16 Dublin 260.76 Paris 436.72 Frankfurt 355.36 Rio de Janeiro 240.87 Hong Kong 346.32 Seoul 310.41 Johannesburg 165.37 Tel Aviv 223.73 Lima 250.08 Toronto 181.25 London 326.76 Warsaw 238.20 Madrid 283.56 Washington, D.C. 250.61 a.Compute the sample mean (to decimals).
b.Compute the sample standard deviation (to decimals).
c.Compute a confidence interval for the population standard deviation (todecimals). Use Table 11.1.
( , )
Question 7Is there any difference in thevariability in golf scores for players on the LPGA Tour (the women'sprofessional golf tour) and players on the PGA Tour (the men's professionalgolf tour)? A sample of tournament scores from LPGA events showed a standarddeviation of strokes, and a sample of tournament scores from PGA events showeda standard deviation of . Conduct a hypothesis test for equal populationvariances to determine whether there is any statistically significantdifference in the variability of golf scores for male and female professionalgolfers. Use .
What is your conclusion?There is significant difference in thevariances. Question 8Stable cost reporting in amanufacturing setting is typically a sign that operations are running smoothly.The accounting department at Rockwell Collins, an avionics manufacturer,analyzes the variance of the weekly costs reported by two of its productiondepartments. A sample of cost reports for each of the two departments showscost variances of and , respectively. Is this sample sufficient to concludethat the two production departments differ in terms of unit cost variance? Use(to decimals).
ANSWER WILL BE SENT BY EMAIL.
Question 2The competitive advantage of somesmall American factories such as In Tolerance Contract Manufacturing lies intheir ability to produce parts with very narrow requirements, or tolerances,that are typical in the aerospace industry. Consider a product withspecifications that call for a maximum variance in the lengths of the parts of. Suppose the sample variance for parts turns out to be . Use , to test whetherthe population variance specification is being violated. : Test statistic = (to2 decimals, if required)The -value is . Use Table 11.1.
Question 3In its Auto Reliability Survey, Consumer Reports asked subscribersto report their maintenance and repair costs. Most individuals are aware of thefact that the average annual repair cost for an automobile depends on the ageof the automobile. A researcher is interested in finding out whether thevariance of the annual repair costs also increases with the age of theautomobile. A sample of automobiles years old showed a sample standarddeviation for annual repair costs of and a sample of automobiles years oldshowed a sample standard deviation for annual repair costs of .a. State the null and alternative versions of the research hypothesisthat the variance in annual repair costs is larger for the older automobiles.Let year old automobiles be represented by population .b. At a level of significance, what is your conclusion? Calculate the value of the test statistic (to decimals).The -value is . Use Table 4 of Appendix B.that year old automobiles have a larger variance in annual repair costscompared to year old automobiles.
Question 4The variance in a production process is an important measure of the qualityof the process. A large variance often signals an opportunity for improvementin the process by finding ways to reduce the process variance. Jelly BellyCandy Company is testing two machines that use different technologies to fillthree pound bags of jelly beans. The file Bags contains a sample ofdata on the weights of bags (in pounds) filled by each machine.Conduct astatistical test to determine whether there is a significant difference betweenthe variances in the bag weights for the two machines. Use a level ofsignificance. What is your conclusion? Which machine, if either, provides thegreater opportunity for quality improvements? Click on the datafile logo toreference the data. (todecimals)(todecimals)(todecimals) Question 5Battery life is an important issuefor many smartphone owners. Public health studies have examined"low-battery anxiety" and acute anxiety called "nomophobia"that results when a smartphone user's phone battery charge runs low and thendies (Wall Street Journal, May , ). Battery life between charges for theSamsung Galaxy S9 averages hours when the primary use is talk time and hourswhen the primary use is Internet applications. Because the mean hours for talktime usage is greater than the mean hours for Internet usage, the question wasraised as to whether the variance in hours of usage is also greater when theprimary use is talk time. Sample data showing battery life between charges forthe two applications follows. Click on the datafile logo to reference the data. Primary Use: Talking 35.8 22.2 24.0 32.6 18.5 42.5 28.0 23.8 30.0 22.8 20.3 35.5 Primary Use: Internet 14.0 12.5 16.4 11.9 9.9 3.1 5.4 11.0 15.2 4.0 4.7 a. Formulate hypotheses about the two population variances thatcan be used to determine whether the population variance in battery life isgreater for the talk time application. Consider the talk time use as populationand Internet use as population .
b.What are the standard deviations of battery life for the two samples (todecimals)? c.Conduct the hypothesis test and compute the -value.p-value = (todecimals)Using a level of significance, whatis your conclusion?. We that the population variance inbattery hours of use for the talk time application is larger than thepopulation variance in battery hours of use for the Internet application.
Question 6According to the Corporate TravelIndex compiled by Business Travel News, the average daily cost forbusiness travel in the United States rose to per day (Executive Travel website).The file Travel contains sample data for an analogous study on theestimated daily living costs for an executive traveling to variousinternational cities. The estimates include a single room at a four-star hotel,beverages, breakfast, taxi fares, and incidental costs. Click on the datafilelogo to reference the data. City Daily Living Cost ($) City Daily Living Cost ($) Bangkok 242.87 Mexico City 212.00 Bogota 260.93 Milan 284.08 Cairo 194.19 Mumbai 139.16 Dublin 260.76 Paris 436.72 Frankfurt 355.36 Rio de Janeiro 240.87 Hong Kong 346.32 Seoul 310.41 Johannesburg 165.37 Tel Aviv 223.73 Lima 250.08 Toronto 181.25 London 326.76 Warsaw 238.20 Madrid 283.56 Washington, D.C. 250.61 a.Compute the sample mean (to decimals).
b.Compute the sample standard deviation (to decimals).
c.Compute a confidence interval for the population standard deviation (todecimals). Use Table 11.1.
( , )
Question 7Is there any difference in thevariability in golf scores for players on the LPGA Tour (the women'sprofessional golf tour) and players on the PGA Tour (the men's professionalgolf tour)? A sample of tournament scores from LPGA events showed a standarddeviation of strokes, and a sample of tournament scores from PGA events showeda standard deviation of . Conduct a hypothesis test for equal populationvariances to determine whether there is any statistically significantdifference in the variability of golf scores for male and female professionalgolfers. Use .
What is your conclusion?There is significant difference in thevariances. Question 8Stable cost reporting in amanufacturing setting is typically a sign that operations are running smoothly.The accounting department at Rockwell Collins, an avionics manufacturer,analyzes the variance of the weekly costs reported by two of its productiondepartments. A sample of cost reports for each of the two departments showscost variances of and , respectively. Is this sample sufficient to concludethat the two production departments differ in terms of unit cost variance? Use(to decimals).
ANSWER WILL BE SENT BY EMAIL.
