The owner of the Pizza Shack in Exercises 9.177 and 9.178 does not understand the use of the normal distribution and z in Exercise 9.178. Help the manager interpret the meaning of the results by redoing both hypothesis tests using x = number of customers preferring the new crust as the test statistic and its binomial probability distribution. Use a one-tailed test with Ha: p = 0.50 and a = 0.02 The results were as follows: on Tuesday afternoon, they sampled 15 customers and 9 preferred the new pizza crust; on Friday evening, they sampled 200 customers and found 120 preferred the new pizza crust.
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?