2 The back-to-back stem-and-leaf diagram below shows the number of hours of television watched per week by each of 15 boys and 15 girls.
$$\begin{aligned}
& \text { Boys Girls }
& \left. \begin{array} { r r r r r r r r | r r r r r r r r r r r r r }
& 677664 & 4 & 3 & 0 & 0 & 5 & 5 & 6 & 677888
\end{array} \right\}
\end{aligned}$$
Key: 4 | 2 | 2 means a boy who watched 24 hours and a girl who watched 22 hours of television per week.
- Find the median and the quartiles of the results for the boys.
- Give a reason why the median might be preferred to the mean in using an average to compare the two data sets.
- State one advantage, and one disadvantage, of using stem-and-leaf diagrams rather than box-andwhisker plots to represent the data.