Suppose the average size of a new house built in a certain county in 2010 was 2,272 square feet. A random sample of 25 new homes built in this county was selected in 2014.

The average square footage was 2,190, with a sample standard deviation of 225 square feet.

a. Using a = 0.02, does this sample provide enough evidence to conclude that the average house size of a new home in the county has changed since 2010?

b. Estimate the p-value for this test using Table 5 in Appendix A.

c. Determine the precise p-value for this test using Excel.

d. Use PHStat to validate these results.

AppendixLO1