5. In 1970, a bottle of dishwashing detergent cost $0.50. To answer each of the parts below, assume that the consumer price index (CPI) was 29.6 in 1960, 38.8
in 1970, and 82.4 in 1980.
(5 points: Part 1 - 2 points; Part II - 2 points; Part III - 1 point)
Part I: If the price of dishwashing detergent increased at the same rate as the CPI
from 1970 to 1980, how much did a bottle of dishwashing detergent cost in
1980? By how much did the price of a bottle of dishwashing detergent increase
from 1970 to 1980?