9 A random sample of 8 students is chosen from those sitting examinations in both Mathematics and French. Their marks in Mathematics, \(x\), and in French, \(y\), are summarised as follows.
$$\Sigma x = 472 \quad \Sigma x ^ { 2 } = 29950 \quad \Sigma y = 400 \quad \Sigma y ^ { 2 } = 21226 \quad \Sigma x y = 24879$$
Another student scored 72 marks in the Mathematics examination but was unable to sit the French examination.
- Estimate the mark that this student would have obtained in the French examination.
- Test, at the \(5 \%\) significance level, whether there is non-zero correlation between marks in Mathematics and marks in French.