A pizza delivery chain advertises that it will deliver your pizza in 30 minutes from when the order is placed. Being a skeptic, you decide to test and see if the mean delivery time is actually more than 30 minutes. For the simple random sample of 9 customers who record the amount of time it takes for each of their pizzas to be delivered, the mean is 35.4 minutes with a standard deviation of 7.6 minutes. Assume that the population distribution is approximately normal. Required:
a. Perform a hypothesis test using a 0.05 level of significance.
b. State the null and alternative hypotheses for the test.