The CPI was 116.5 in 2010 and 126.6 in 2015.
a) What was the overall percent inflation during this period?
b) How much would a worker earning $50,000 in 2010 have to earn
in2015 in order to keep pace with inflation?



Answer :

Certainly! Let's break down the solution to the problem into two parts.

### Part (a): Calculate the overall percent inflation during the period

The formula to calculate the percent inflation over a period is:

[tex]\[ \text{Percent Inflation} = \left(\frac{\text{CPI in Final Year} - \text{CPI in Initial Year}}{\text{CPI in Initial Year}}\right) \times 100 \][/tex]

Given:
- CPI in 2010 = 116.5
- CPI in 2015 = 126.6

Substitute these values into the formula:

[tex]\[ \text{Percent Inflation} = \left(\frac{126.6 - 116.5}{116.5}\right) \times 100 \][/tex]

First, find the difference in CPI:

[tex]\[ 126.6 - 116.5 = 10.1 \][/tex]

Next, divide this difference by the CPI in 2010:

[tex]\[ \frac{10.1}{116.5} \approx 0.0867 \][/tex]

Finally, multiply by 100 to express it as a percentage:

[tex]\[ 0.0867 \times 100 \approx 8.67\% \][/tex]

So, the overall percent inflation during the period from 2010 to 2015 is approximately 8.67%.

### Part (b): Calculate the required salary in 2015 to keep pace with inflation

To find out how much a worker earning [tex]$50,000 in 2010 would need to earn in 2015 to keep pace with inflation, we use the ratio of the CPI values from the two years. Given: - Salary in 2010 = $[/tex]50,000
- CPI in 2010 = 116.5
- CPI in 2015 = 126.6

The formula to adjust the salary is:

[tex]\[ \text{Adjusted Salary} = \text{Salary in Initial Year} \times \left(\frac{\text{CPI in Final Year}}{\text{CPI in Initial Year}}\right) \][/tex]

Substitute the values:

[tex]\[ \text{Adjusted Salary} = 50{,}000 \times \left(\frac{126.6}{116.5}\right) \][/tex]

First, compute the ratio of the CPIs:

[tex]\[ \frac{126.6}{116.5} \approx 1.0867 \][/tex]

Next, multiply this ratio by the salary in 2010:

[tex]\[ 50{,}000 \times 1.0867 \approx 54{,}335 \][/tex]

So, to keep pace with inflation, a worker who earned [tex]$50,000 in 2010 would need to earn approximately $[/tex]54,335 in 2015.