9 There are a large number of students at a particular college. The heights, in metres, of a random sample of 8 students are as follows.
$$\begin{array} { l l l l l l l l }
1.75 & 1.72 & 1.62 & 1.70 & 1.82 & 1.75 & 1.68 & 1.84
\end{array}$$
You may assume that heights of students are normally distributed.
- Test, at the \(5 \%\) significance level, whether the population mean height of students at this college is greater than 1.70 metres.
- Find a \(95 \%\) confidence interval for the population mean height of students at this college.