225k views
4 votes
A town has a population of 17000 and grows at 4% every year. What will be the population after 12 years?

User Heng
by
4.3k points

1 Answer

2 votes

Answer:

27,218

Explanation:

After the first year, the population has grown by 4% of 17000, which is 0.04 times 17000 or 680. Therefore, the new population is 17000 + 680 or 17680.

After the second year, the population has grown by 4% of 17680, which is 0.04 times 17680 or 707.2. Of course, there's no such thing as 0.2 of a person, but we're just approximating, so that's ok. That brings the new total to 17680 + 707.2, which is 18387.2.

We could keep doing this for 12 years, but there's a shortcut. Since we're adding 4% each year, the new population is 104% of the old population. Therefore, we are multiplying by 104% each year. 104% is the same as 1.04. If we multiply 17000 by 1.04 12 times, we have something like this:

17000 * 1.04 * 1.04 * 1.04 * .... * 1.04

Another way to write that is using powers or:

17000 * 1.04^12

which gives us 27217.54, which we can round to 27,218 people.

User ShowFocus
by
4.2k points