- A teacher asked a random sample of 10 students to record the number of hours of television, \(t\), they watched in the week before their mock exam. She then calculated their grade, \(g\), in their mock exam. The results are summarised as follows.
$$\sum t = 258 \quad \sum t ^ { 2 } = 8702 \quad \sum g = 63.6 \quad \mathrm {~S} _ { g g } = 7.864 \quad \sum g t = 1550.2$$
- Find \(\mathrm { S } _ { t t }\) and \(\mathrm { S } _ { g t }\)
- Calculate, to 3 significant figures, the product moment correlation coefficient between \(t\) and \(g\).
The teacher also recorded the number of hours of revision, \(v\), these 10 students completed during the week before their mock exam. The correlation coefficient between \(t\) and \(v\) was -0.753
- Describe, giving a reason, the nature of the correlation you would expect to find between \(v\) and \(g\).