The monthly incomes for

12

randomly selected people, each with a bachelor's degree in economics, are shown on the right. Complete parts (a) through (c) below.

Assume the population is normally distributed.

4450.62	4596.26	4366.86
4455.92	4151.35	3727.74
4283.35	4527.63	4407.27
3946.89	4023.66	4221.91

Question content area bottom

Part 1

(a) Find the sample mean.

Part 2

(b) Find the sample standard deviation.

Part 3

(c) Construct a

90%

confidence interval for the population mean

mu.

A

90%

confidence interval for the population mean is

(enter your response here,enter your response here).