S5.9 Understand that increasing sample size generally leads to better estimates of probability and population characteristics.
Candidates should be able to:
understand that the greater the number of trials in an experiment the more reliable the results are likely to be
understand how a relative frequency diagram may show a settling down as sample size increases, enabling an estimate of a probability to be reliably made; and that if an estimate of a probability is required, the relative frequency of the largest number of trials available should be used
Notes
Refer also to S5.7 and S5.8.
Examples
From a relative frequency diagram: Use the diagram to make the best estimate of the probability of picking a red disc.
Aisha catches 10 frogs at random from a pond and measures their weight. She then uses the data to estimate the mean weight of a frog in the pond. How could she obtain a more reliable estimate for this mean?
The table shows the number of heads obtained in every 10 flips of a coin.
Trials
1st 10
2nd 10
3rd 10
4th 10
5th 10
Number of heads
3
2
2
1
2
Draw a relative frequency graph for this data (graph paper available) Use your graph or otherwise obtain an estimate of the probability of a head for this coin.