the population density of New Mexico increased at a relatively constant rate from 1980 to 1999. in 1985, the population density was about 11.62 people per square mile. in 1999, the population density was about 14.25 people per square mile. Write an equation that gives the population density (in square mile) as a function of the number of years since 1980. what was the population density in 1990.

I already know the slope is 263/1400, I'm just confused on what to do next.

Question

the population density of New Mexico increased at a relatively constant rate from 1980 to 1999. in 1985, the population density was about 11.62 people per square mile. in 1999, the population density was about 14.25 people per square mile. Write an equation that gives the population density (in square mile) as a function of the number of years since 1980. what was the population density in 1990.

I already know the slope is 263/1400, I'm just confused on what to do next.