Step by step
The question
Question: A coin is flipped 100 times and lands heads 47 times.
Find the experimental probability of heads.
1 Times it happened over times tried
It happened 47 times out of 100 flips.
So the experimental probability is 47/100.
P(heads) = 47100
Experimental probability comes from what really happened in the experiment.
experimental = what really happened
As a percent: 100 times 1 is 100.
47 times 1 is 47.
So it is 47%.
= 47 × 1100 × 1 = 47100 = 47%
2 Compare with the theory
In theory, a coin has 2 sides, so heads is 1 out of 2: 50%.
= theory: 12 = 50%
Careful!
That is the theory.
The question asks what really happened: 47%.
Careful: not P(heads) = 50% ✗
47% is close to 50%.
With more flips, it usually gets even closer.
= 47% < 50%
3 Check
Let's check: 47% of 100 flips should be the 47 times.
47% of 100 is 47.
So the answer is right!
47% of 100 = 47
Let's look back.
First: times it happened over times tried.
Then: compare with the theory.
Last: check.
Answer
= 47 × 1100 × 1 = 47100 = 47%