Please, solve this problem.

1.Your local take-out restaurant claims that their food is delivered in 20 minutes. You decide to test their claim and order food from them 36 times over the next 3 months. On average, the food is delivered in 23 minutes with a standard deviation of 5 minutes. a.What is the null hypothesis? b.Would you reject or not reject the null hypothesis? Show your work to support your decision. 2.Based on your answer to Question 1, construct a 95% confidence interval for the true value of the delivery time.