18 of 45 voters like the plan. About how many of 2,000 like the plan?

Step by step

The question

Question: 18 of 45 voters like the plan.

About how many of 2,000 like the plan?

1 The fraction in the sample

18 out of 45: that is 18/45.

The 45 voters are a sample: a small group that stands for everyone.

18 and 45 can both be divided by 9.

So it is 2/5.

2 Use it for everyone

We expect the same fraction of all 2,000: 2/5 of 2,000.

Of means times.

2,000 divided by 5 is 400.

Then times 2.

That is about 800.

Careful!

A sample only shows about how many.

So the answer is a good guess, not an exact count.

So about 800 voters like the plan.

3 Check

Let's check: 800 out of 2,000.

Divide the top and the bottom by 400: 2/5, the same fraction as the sample.

So the answer is right!

Let's look back.

First: the fraction in the sample.

Then: use it for everyone.

Last: check.