1)

Describe the difference between a t-distribution with 2 degrees of freedom and a t-distribution with 20 degrees of freedom.

2)

Other than using t instead of z, what other differences are there between constructing a z-interval and constructing a t-interval?

3)

A manufacturer of small appliances employs a market research firm to estimate retail sales of its products. Here are last month's sales of electric can openers from an SRS of 20 stores in the Midwest sales region:

19 19 16 19 25 26 24 63 22 16

13 26 34 10 48 16 20 14 13 24

Find the 95% t confidence interval for the mean.