18 Jennie is a piano teacher who teaches nine pupils.
She records how many hours per week they practice the piano along with their most recent practical exam score.
| Student | Practice (hours per week) | Practical exam score (out of 100) |
| Donovan | 50 | 64 |
| Vazquez | 6 | 71 |
| Higgins | 3 | 55 |
| Begum | 2.5 | 47 |
| Collins | 1 | 80 |
| Coldbridge | 4 | 61 |
| Nedbalek | 4.5 | 65 |
| Carter | 8 | 83 |
| White | 11 | 92 |
She plots a scatter diagram of this data, as shown below.
\includegraphics[max width=\textwidth, alt={}, center]{8d9ace4b-0c15-48bd-9b0d-302f57ea9759-20_862_1516_1434_262}
18
- Identify two possible outliers by name, giving a possible explanation for the position on the scatter diagram of each outlier.
First outlier \(\_\_\_\_\)
Possible reason \(\_\_\_\_\)
Second outlier \(\_\_\_\_\)
Possible reason \(\_\_\_\_\)
18 - Jennie discards the two outliers.
18 - Describe the correlation shown by the scatter diagram for the remaining points.
18
- (ii) Interpret this correlation in the context of the question.
In the past, he has found that \(70 \%\) of all seeds successfully germinate and grow into cucumber plants.
He decides to try out a new brand of seed.
The producer of this brand claims that these seeds are more likely to successfully germinate than other brands of seeds.
Martin sows 20 of this new brand of seed and 18 successfully germinate.
Carry out a hypothesis test at the \(5 \%\) level of significance to investigate the producer's claim.