Question

In a small town named Danville, the population today is 6999. For the last sixyears, the population has grown by 20% every year. If the growth stay thesame, what is the expected population in Danville 4 years from today?

Answer 1

We have that the population of Danville today is 6999.

The growth is 20% by year.

And they ask for the population in 4 years from today.

We just need to predict the population for the following 4 years, in other words, add 20% of the population each year.

1. 20% of 6999:

$6999\ast\frac{20}{100}=1399.8$

Then the population one year later will be:

$6999+1399.8=8398.8\approx8398$

For the second year:

$8398+(8398\ast\frac{20}{100})=10077.6\approx10077$

For the third year:

$10077+(10077\ast\frac{20}{100})=12092.4\approx12092$

For the fourth year:

$12092+(12092\operatorname{\ast}\frac{20}{100})=14510.4\approx14510$

Then, the correct answer is that the population in Danville 4 years from today will be 14510.