You decide to order 32 pizzas from Pizza Hut and record the…

You decide to order 32 pizzas from Pizza Hut and record the delivery times. For the 32 pizzas, the average delivery time turns out to be 29 minutes with a sample standard deviation of 2.5 minutes. (a) Would you use a Normal Distribution or T-Distribution to calculate a confidence interval for this example?  [type] (b) What is a 90% confidence interval for the true average delivery time for Pizza Hut ? [conf]