Expenditures for what? In what year? What do the second "given" column of numbers represent?
I can't imagine CPI itself going down by that much (15.5%) from 2001 to 2002. It hardly ever goes down.
You must have left some information, as well as definitions, out of your question.
How to calculate the CPI for expenditures?
Given:
2001 $645
2002 $545
1 answer