The Emerald City's population density shrunk throughout the 1970s. In 1970, the population density was approximately 7740 people per square mile, and it was shrinking at a rate of 0.79 percent per year.
a) If this trend had continued, find a formula for the population density, , of the Emerald City years after 1970.

b) Assuming this trend continues, predict the population density of the Emerald City in 1987 using your function from part (a).
people per square mile