Problem

Prison Sentences The proportion of those convicted in federal court who are imprisoned has...

Prison Sentences The proportion of those convicted in federal court who are imprisoned has been increasing. The table shows the number of those imprisoned for selected years from 1980 to 2007.

Year	Number Imprisoned
1980	13,766
1985	20,605
1990	28,659
1995	31,805
2000	50,451
2005	61,151
2006	63,699
2007	62,883

a. Use the data to create a linear equation that models the number of those imprisoned as a function of the number of years after 1980.
b. Use the model to estimate the number imprisoned in 2002. Is this interpolation or extrapolation?
c. Use the model to determine in what year the number will be 78,750.