Step by step
The question
Question: A spinner landed on blue 12 times in 40 spins.
Predict the blues in 200 spins.
1 Times it happened over times tried
It happened 12 times out of 40 spins.
So the experimental probability is 12/40.
P(blue) = 1240
Experimental probability comes from what really happened in the experiment.
experimental = what really happened
12 and 40 can both be divided by 4.
So it is 3/10.
= 12 ÷ 440 ÷ 4 = 310
2 Predict
We expect the same fraction in 200 spins: 3/10 of 200.
Of means times.
= 310 × 200
200 divided by 10 is 20.
200 ÷ 10 = 20
Then times 3.
= 3 × 20
So about 60.
= ≈ 60
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: 60 out of 200 is 3/10, the same fraction as before.
So the answer is right!
60200 = 310
Let's look back.
First: times it happened over times tried.
Then: predict.
Last: check.
Answer
Careful: about, not exactly: chance can change it