Help calculating inflation rate with GDP deflators?

Question

Example Question:

What is the inflation rate between 2002 and 2003?
2003 deflator: 2.8
2002 deflator: 2.1

Answer 1

It would take $2.10 in 2002 and $2.80 to buy what $1.00 bought in the base year. The inflation rate is the percent change in the value of $1.00 between 2002 and 2003.
2002 dollar is worth 1/2.1= .476
2003 dollar is worth 1/2.8= .357
the change is .119 and the % change is .119/.476=.25 or 25%