CCN and ActMedia provided a television channel targeted to individuals waiting in supermarket checkout lines. The channel showed news, short features, and advertisements. The length of the program was based on the assumption that the population mean time a shopper stands in a supermarket checkout line is 8 minutes. A sample of actual waiting times will be used to test this assumption and determine whether actual mean waiting time differs from the standard.
a. Formulate the hypothesis for this application.
b. A sample of 120 shoppers showed a sample mean waiting time of 8.5 minutes. Assume a population standard deviation of 3.2 minuest. What is the p-value?
c. At a=.0t what is your conclusion?
d. Compute a 95% confidence interval for the population mean. Does it support your conclusion?
E. Compute the probability of Type II errors if the true value of population mean is 9 minutes, and the sample size 120