In a sample of 250 seeds, 35 were bad. About how many of 5,000 are…

Step by step

The question

Question: In a sample of 250 seeds, 35 were bad.

About how many of 5,000 are bad?

1 The fraction in the sample

35 out of 250: that is 35/250.

The 250 seeds are a sample: a small group that stands for everyone.

35 and 250 can both be divided by 5.

So it is 7/50.

2 Use it for everyone

We expect the same fraction of all 5,000: 7/50 of 5,000.

Of means times.

5,000 divided by 50 is 100.

Then times 7.

That is about 700.

Careful!

A sample only shows about how many.

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

So about 700 seeds are bad.

3 Check

Let's check: 700 out of 5,000.

Divide the top and the bottom by 100: 7/50, 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.