Step by step
The question
Question: In a sample of 60 eggs, 3 were cracked.
About how many of 1,500 are cracked?
1 The fraction in the sample
3 out of 60: that is 3/60.
360
The 60 eggs are a sample: a small group that stands for everyone.
sample: 60 eggs
3 and 60 can both be divided by 3.
So it is 1/20.
= 3 ÷ 360 ÷ 3 = 120
2 Use it for everyone
We expect the same fraction of all 1,500: 1/20 of 1,500.
Of means times.
= 120 × 1,500
1,500 divided by 20 is 75.
= 75
1,500 ÷ 20 = 75
That is about 75.
= ≈ 75
Careful!
A sample only shows about how many.
So the answer is a good guess, not an exact count.
Careful: about, not exactly
So about 75 eggs are cracked.
3 Check
Let's check: 75 out of 1,500.
Divide the top and the bottom by 75: 1/20, the same fraction as the sample.
So the answer is right!
751,500 = 75 ÷ 751,500 ÷ 75 = 120
Let's look back.
First: the fraction in the sample.
Then: use it for everyone.
Last: check.
Answer
Careful: about, not exactly