How to solve using excel formulas??

A B D F G H J 3 Problem 1: A random sample of 81 students at a local university showed that they work an average of 100 hours per month. The population standard deviation is known to be 27 hours. Answer the 4 questions below. 4 5 6 7 - 8 a) What is the point estimate for the mean hours per month all students at the university work 9 10 b) 95% confidence interval is 11 12 c) 99% confidence interval is 13 d) 14 Type here which interval is wider. Why? - 15 16 17 18 10