Business Stat. Questions

1.) 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?

Don't use plagiarized sources. Get Your Custom Essay on
Need an answer from similar question? You have just landed to the most confidential, trustful essay writing service to order the paper from.
Just from $11/Page
Order Now

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

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

d. Use PHStat to validate these results.

2. Consumers with credit scores below 600 have a very difficult time getting approved for car or mortgage loans. In 2012, 24% of Americans had a credit score below 600. Due to the recent financial crisis, the federal government is concerned that this proportion has increased. To test this hypothesis, a random sample of 250 Americans was chosen in 2014. From this sample, 67 people had credit scores less than 600. Using a = 0.10, answer the following below:

a. Does this sample provide support for the government’s concern that the proportion of Americans with credit scores below 600 has increased since 2012?

b. Determine the p-value for this test.

c. Verify your results using PHStat.