- Robin shoots 8 arrows at a target each day for 100 days.
The number of times he hits the target each day is summarised in the table below.
| Number of hits | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| Frequency | 1 | 10 | 30 | 34 | 17 | 4 | 2 | 0 | 2 |
Misha believes that these data can be modelled by a binomial distribution.
- State, in context, two assumptions that are implied by the use of this model.
- Find an estimate for the proportion of arrows Robin shoots that hit the target.
Misha calculates expected frequencies, to 2 decimal places, as follows.
| Number of hits | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| Expected frequency | 2.81 | 12.67 | \(r\) | 28.05 | 19.73 | \(s\) | 2.50 | 0.40 | 0.03 |
- Find the value of \(r\) and the value of \(s\)
Misha correctly used a suitable test to assess her belief.
- Explain why she used a test with 3 degrees of freedom.
- Complete the test using a \(5 \%\) level of significance. You should clearly state your hypotheses, test statistic, critical value and conclusion.