Experimental Probability
11+ Maths, topic 5.1.3
Experimental Probability
You may be given the results of an experiment and be asked to calculate the possibility of an event happening. This is called experimental probability.
Example question - rolling dice
- Jack rolled a fair dice 20 times.
- Rolling an even number was recorded as a ‘win’ and rolling an odd number as a ‘lose’. The results are displayed in this table.
- What is the experimental probability of a 'win'?
Experimental probability equation
- To answer this question, you need to know the equation for experimental probability.
Probability of a win
- The number of 'wins' is 12.
- The number of trials is 20.
- So the probability of a win is 12⁄20.
- This fraction can be simplified to 3⁄5.
Test yourself on Experimental Probability
Charlie kicks 20 penalties. He records scores as 'wins' and misses as 'losses'.
What is the experimental probability of a 'win'?Jemima shoots 30 netballs into a hoop.
When she gets the ball in, she records a 'win'. When she misses, she records a 'loss'.
What is the experimental probability of a 'win'?Jack is practising 100m sprints. When he finishes in under 12s, he records a 'win'. When he takes longer than 12s, he records a 'loss'.
What is the experimental probability of a 'win'?