Price Comparison of Smoothie Blenders. A personal fitness company produces both a deluxe and a standard model of a smoothie blender for home use. Selling prices obtained from a sample of retail outlets follow:

Retail Outlet

Model Price

Deluxe

Standard

1

39

27

2

39

28

3

45

35

4

38

30

5

40

30

6

39

34

7

35

29

The manufacturer’s suggested retail prices for the two models show a $10 price differential. Use a .05 level of significance and test the mean difference between the prices of the two models is $10.
What is the 95% confidence interval for the difference between the mean prices of the two models?