Question

The population of a suburb of Cincinnati has shown a linear growth in the years 1991-2006. The population in 1991 was 21400 people and it has been growing at a rate of 625 people per year.

Answer 1

Let t be the number of years after 1991, since the population has been growing at a rate of 625 people per year and the population in 1991 was 21400 people, then we can set the following equation:

`P=21400+625t\text{.}`

Now, if this behavior continues, then the population in 2008 will be:

`P=21400+625\cdot(2008-1991_{})\text{.}`

Simplifying the above equation we get:

`\begin{gathered} P=21400+625\cdot17, \\ P=21400+10625, \\ P=32025. \end{gathered}`

Answer:

(a)

`P=21400+625t\text{.}`

(b)

`32025.`