Question: 45 The policy of a particular bank branch is that its ATMs must be stocked with enough cash to satisfy customers making withdrawals over an entire weekend. Customers goodwill depends on such services meeting customer needs. At this branch the expected (i.e. population) mean amount of money withdrawn from ATMs per customer transaction over the weekend is $160 with an expected (i.e. population) standard deviation of $30. Suppose that a random sample of 36 customers transactions is examined, and it is observed that the sample mean withdraw is $172.

a) At the 0.05 level of significance, using the critical value approach to hypothesis testing, is there evidence to believe that the true mean withdrawal is greater than $160?

b) At the 0.05 level of significance, using p-value approach to hypothesis testing, is there evidence to believe that the true mean withdrawal is grater than $160?