Suppose that you consider the confidence interval found in Q…
Suppose that you consider the confidence interval found in Question 22 to be too wide. You want to be able to estimate the difference between the two population proportions with a sampling error of no more than SE=0.03 (or 3%) at the 95% confidence level. To be conservative, assume that no reliable estimate for p1 and p2 are available, so use p1=p2=.5 for your computations. If you going to use independent random samples of the same size, how large should the sample sizes be?
Read DetailsCustomer satisfaction has been found to drop off dramaticall…
Customer satisfaction has been found to drop off dramatically when customers have to wait more than 2.5 minutes in a check-out lane at the grocery store. A random sample of 64 customers’ wait time yielded a mean time of 2.96 minutes. The standard deviation of the sample was 1.04 minutes. Using alpha = 0.05, we want to test whether the average wait time is significantly greater than 2.5 minutes. What are the correct Hypotheses and the correct test statistic?
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