Question

Salaries of 45 college graduates who took a statistics course in college have a​ mean, overbar x​, of comma $65,500. Assuming a standard​ deviation, sigmaσ​, of ​$14 comma 14,971​, construct a 99​% confidence interval for estimating the population mean μ.

$ less than< μless than<​$

Answer 1

Given:

Sample mean = = 65,500

Population standard deviation = = 14,971

Confidence level = 0.99

Level of significance = = 1-0.99 = 0.01

The critical value Zc = 2.576 ...Using excel, =NORMSINV(1-(0.01/2))

The 99% confidence interval for population mean is,

Hence, 99% confidence interval is 59751.406 71248.594

Done