Question: A manufacturer produces both a deluxe and a standard model of an automatic sander designed for home use. Selling prices obtained from a sample of retail outlet follow:

Model Price ($) Model Price ($)

Retail Outlet Deluxe Standard Retail Outlet Deluxe Standard

1 39 27 5 40 30

2 39 28 6 39 34

3 45 35 7 35 29

4 38 30

a. The manufacturer’s suggested retail prices for the two models show a $10 price diferential. Use a .05 level of significance and test that the mean difference between the prices of the two models is $10.

b. What is the 95% confidence interval for the difference between the mean prices of the two models?