Question

Based on the Consumer Price Index, the rate of inflation in the United States between 1980 and 2011 was about 3.3% per year. What salary in 1980 would be equivalent to a $51,000 salary in 2011? Round your final answer to two decimal places.

Answer 1

solution

number of years (n) between 1980 and 2011

$$n=2011-1980=31years$$

Inflation rate (r) $=3.3\%$ per year

Let X be the salary in 1980. The salary equivalent in 2011 is given by:

$$X*(1+r)^n$$

Therefore

$$X*(1+0.033)^{31}= 51,000$$

$$X = \frac{51,000}{(1+0.033)^{31}}$$

$$=18,640.61$$

answer: 1980 salary would be $18,640.61