In Excel

1.) Find the 90% confidence intervals for population mean for the following

a.) sample mean is 53 and = 7.1 for n = 90

b.) sample mean is 149.7 and s = 23.8 for n = 20

2.) Using the level of significance of .05, test the claim that the average number of classes skipped by students is less than 5. The sample data used to test the claim is as follows:

3, 3, 6, 4, 1, 2, 7, 4, 3, 2, 0, 5, 0, 1, 2, 4, 0, 3, 6, 1

a. Find the mean and sample standard deviation.

b. Find the test value using TTest on your calculator.

c. Find the p-value using T.dist on Excel 

d. Find the critical value using T.inv on Excel

3.) Using the level of significance of .01, test the claim that the proportion of college students who are not on financial aid of any sort is greater than 15%.  

a. Find the test value using 1-PropZtest on your calculator if 241 students out of 1000 students surveyed are not on any financial aid.

b. Find the p-value using Norm.s.dist on Excel

c. Find the critical value using Norm.s.inv on Excel