I need help with two questions regarding CPI (consumer price index). First, based on the assumption that the inflation rate is 3% from 1997 to 2007, what would the CPI be in 2007 (I am looking for the formula to figure it out).

Second; how to calculate the CPI in the current year and 5 years from now and then figure out what the cost of an item would be 5 years from now.

Any help would be appreciated, thanks!