2. In 1984, a school bus cost $20,000. To answer each of the parts below, assume that the consumer price index (CPI) was 36.8 in 1970, 100 in 1984, and 140.7 in 1992. (5 points: Part I - 2 points; Part II - 2 points; Part III - 1 point)

Part I: If the price of a school bus increased at the same rate as the CPI from 1970 to 1984, how much did a school bus cost in 1970? By how much did the price of a school bus increase from 1970 to 1984? (2 points: 1 point each)

Part II: If the price of a school bus increased at the same rate as the CPI from 1984 to 1992, how much did a school bus cost in 1992? By how much did the price of a school bus increase from 1984 to 1992? (2 points: 1 point each)

Part III: If a school bus cost $4100 in 1950, and if the price of a school bus increased at the same rate as the CPI from 1950 to 1984, what was the CPI to the nearest tenth in 1950? (1 point)