Geoff is the proud owner of a restaurant. recently he read an article in food weekly which stated that the population mean preparation time for food at popular restaurants is equal to 21 minutes. a footnote at the bottom of the article said that the population standard deviation of preparation times was equal to 7 minutes. geoff is interested in determining whether his restaurant has the same average preparation time as the popular restaurants described in the magazine article. geoff timed how long it took to prepare 33 randomly selected meals over a week. the mean preparation time for the sample was calculated as 19 minutes. geoff would like to use his sample to construct a hypothesis test with h0: μ = 21 and ha: μ ≠ 21.