Chance experiments
Compare expected and actual results.
Testing a dice
Is this dice fair? We can test it with an experiment. Compare what we expect with what happens.
Expected frequency
If we roll 60 times, we expect about 10 sixes. This is the expected frequency. Real results will vary a little.
Actual results
Every number came up between 8 and 12 times. That is close to the expected 10. The dice seems fair.
Spotting bias
32 sixes is far more than 10. The dice is probably biased (unfair). More trials would make us more sure.
What I learnt
- I can calculate expected frequency.
- I can compare results with expectations.
- I can spot possible bias.