Step by step
The question
Question: A spinner landed on green 7 times in 20 spins.
Predict the greens in 300 spins.
1 Times it happened over times tried
It happened 7 times out of 20 spins.
So the experimental probability is 7/20.
P(green) = 720
Experimental probability comes from what really happened in the experiment.
experimental = what really happened
2 Predict
We expect the same fraction in 300 spins: 7/20 of 300.
Of means times.
= 720 × 300
300 divided by 20 is 15.
300 ÷ 20 = 15
Then times 7.
= 7 × 15
So about 105.
= ≈ 105
Careful!
A prediction is only about how many.
The next spins can come out a bit different.
Careful: about, not exactly: chance can change it
3 Check
Let's check: 105 out of 300 is 7/20, the same fraction as before.
So the answer is right!
105300 = 720
Let's look back.
First: times it happened over times tried.
Then: predict.
Last: check.
Answer
Careful: about, not exactly: chance can change it