The Consumer Price Index (CPI ) is the U.S. government’s measure of the prices consumers pay for the things they buy. The government calculates inflation by changes in the CPI.
The table below shows the CPI at different years.
Year 1950 1960 1970 1980 1990 2000
CPI 24.1 29.6 38.8 82.4 130.7 172.2
Fill in the table below by calculating the percentage change in the CPI over each decade.

Question

The Consumer Price Index (CPI ) is the U.S. government’s measure of the prices consumers pay for the things they buy. The government calculates inflation by changes in the CPI.
The table below shows the CPI at different years.
Year 1950 1960    1970   1980   1990    2000
CPI 24.1     29.6     38.8     82.4    130.7   172.2 
Fill in the table below by calculating the percentage change in the CPI over each decade.

dape · Answer

The percent change is given by dividing the new CPI by the old one. For example the percentage change in CPI from 1950 to 1960 is
$$ \frac{CPI_{1960}}{CPI_{1950}} = \frac{29.6}{24.1} \approx 1.228 = 122.8\% $$

dape · Answer

To clarify, the CPI has gone up by 22.8% in 1960 relative to 1950. If the value above was 95%, the CPI would have gone down by 5%.