Chapter 9 Exercise 1212. The American Sugar Producers Association wants to estimate the mean yearly sugar consumption. A sample of 16 people reveals the mean yearly consumption to be 60 pounds with a standard deviation of 20 pounds.A. What is the value of the population mean? What is the best estimate of this value?Answer: The population mean is unknown because the sum of the values is not known. The best estimate is 60 pounds, which is also the sample mean.The population mean is the sum of all the values in the population divided by the number of values in the population.B. Explain why we need to use the t distribution. What assumption do you need to make?Answer: We need to use th ...view middle of the document...
The quality-assurance department found in a sample of 50 customers at the Warren Road MacBurger that the mean waiting time was 2.75 minutes. At the .05 significance level, can we conclude that the mean waiting time is less than 3 minutes?A) State the null hypothesis and the alternate hypothesis.Answer:Hoµ ≥ 3 MinutesH1µ < 3 MinutesB) State the decision rule.Answer: Reject Ho if Z< 1.65C)Answer: Z= X - µ = 1.767 found by: 3.0 - 2.75 = 1.767σ / √n 1 / √50D) Answer: Ho is rejected.E) What is the p-value? Interpret itAnswer: We can conclude that the mean waiting time is less than 3 minutes at the .05 significance level. If H0 is were to be true, there would be no chance in getting a statistic this small.Chapter 12 Exercise 30There are four auto body shops in a community and all claim to promptly serve customers.To check if there is any difference in service, customers are randomly selected from each repair shop and their waiting times in days are recorded. The output from a statistical software package is:SummaryGroupsCountSumAverageVarianceBody Shop A315.45.1333330.323333Body Shop B43281.433333Body Shop C525.25.040.748Body Shop D425.96.4750.595833ANOVASource of VariationSSdfMSFp-valueBetween Groups23.3732137.7910699.6125060.001632Within Groups9.726167120.810514Total33.0993815Question: Is th...