you are the manager of a restaurant for a​ fast-food franchise. last​ month, the mean waiting time at the​ drive-through window for branches in your geographical​ region, as measured from the time a customer places an order until the time the customer receives the​ order, was 3.6 minutes. you select a random sample of 81 orders. the sample mean waiting time is 3.45 ​minutes, with a sample standard deviation of 0.9 minute. complete parts​ (a) and​ (b) below. question content area bottom part 1 a. at the 0.05 level of​ significance, is there evidence that the population mean waiting time is different from 3.6 ​minutes? state the null and alternative hypotheses.