Is there a difference in the yields of different types ofinvestments? The accompanying data provide yields for aone-year certificate of deposit(CD) and afive-year CD for

25 banks. Complete parts a through c below.

Yields forone-year CDs andfive-year CDs:

Bank 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

One-Year CD 0.4 0.75 0.95 0.3 0.45 0.3 0.45 2.05 0.75 0.55 0.3 0.4 0.3 0.65 1.75 1 1.45 2.25 0.95 1.05 0.5 0.4 0.2 1.05 2

Five-Year CD 4.8 4.85 4.9 3.35 3.95 3.9 3.7 4.3 4.8 4.2 4.4 3.6 4.2 4.9 4.2 4.2 5.1 4.75 5 4.4 4.55 4.1 3.55 4.5 4.05

a. Construct a 90% confidence interval estimate for the mean yield ofone-year CDs.