Experimental probability
Record, describe, and analyse the frequency of outcomes from probability experiments to develop an understanding of relative frequency as an estimate of probability
What a learner can do afterwards
- Conduct a coin-toss experiment, record results in a frequency table, and calculate relative frequencies
- Compare experimental results with theoretical probability and explain discrepancies
- Predict that relative frequency approaches theoretical probability as the number of trials increases
The lesson
You already know the difference between theoretical probability and experimental probability. Relative frequency is the number that describes what actually happened: how many times an outcome occurred, divided by the total number of trials.
To find the relative frequency of heads, divide the number of heads by the total number of tosses: 12 ÷ 20 = 0.6. The theoretical probability of heads is 0.5. Priya's result is close but not exact, because chance affects small numbers of trials.
The more trials you run, the more your relative frequency tends to settle near the theoretical probability. A handful of tosses can look uneven purely by chance.
Relative frequency comes from real trials, and it gets closer to the theoretical probability as you run more of them.
Watch it
Where it sits
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Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.