According to the American Time Use Survey, Americans watched television each weekday for an average of 151 minutes in 2011 (Time, July 11, 2011). Suppose that this result is true for the 2011 population of all American adults. A recent sample of 120 American adults showed that they watch television each weekday for an average of 162 minutes. Assume that the population standard deviation for times spent watching television each weekday by American adults is 30 minutes.
a. Find the p-value for the test of hypothesis with the alternative hypothesis that the current average time spent watching television each weekday by American adults is higher than 151 minutes. What is your conclusion at α = .01?
b. Test the hypothesis of part a using the critical-value approach and α = .01.