Please help me with all parts. Thank you so much!

Q 1.

Suppose that an accounting rm does a study to determine the time needed to complete one person's tax forms. It randomly surveys 150 people. The sample mean is 23.2 hours. There is a known population standard deviation of 6.6 hours. The population distribution is assumed to be normal. NOTE: If you are using a Student's t-distribution, you may assume that the underlying population is normally distributed. (In general, you must rst prove that assumption, though.) El Part (a) Find the following. (Enter exact numbers as integers, fractions, or decimals.) >