The Pizza Shack in Exercise 9.177 has completed its sampling and the results are in! On Tuesday afternoon, they sampled 15 customers and 9 preferred the new pizza crust. On Friday evening, they sampled 200 customers and 120 preferred the new pizza crust. Help the manager interpret the meaning of these results. Use a one-tailed test with Ha: p = 0.50 and a = 0.02 Use z as the test statistic.
a. Is there sufficient evidence to conclude a significant preference for the new crust based on Tuesday’s customers?
b. Is there sufficient evidence to conclude a significant preference for the new crust based on Friday’s customers?
c. Since the percentage of customers preferring the new crust was the same p’ = 0.60 in both samplings, explain why the answers in parts a and b are not the same.