CPI in 1980 is 100 ;1990 158.56; 2000 208.98; 2010 218.06

Retain price of butter 1980 $1.88; 1990 $1.99; 2000 $2.52; $2010$ 2.88

Calculate the real price of butter in 1980 dollars. Has the real price increased/decreased/stayed the same from 1980 to 2000? from 1980 to 2010?

What is the percentage of change in the real price from 1980 to 2000? From 1980 to 2010?

Convert the CPI into 1990=100 and determine the real price of the butter in 1990 Dollars?

What is the percentage change in real price from 1980 to 2000? Compare this with your answer to the percentage change in real price. What do you notice? Explain