1 The heights \(x \mathrm {~cm}\) of 100 boys in Year 7 at a school are summarised in the table below.
| Height | \(125 \leqslant x \leqslant 140\) | \(140 < x \leqslant 145\) | \(145 < x \leqslant 150\) | \(150 < x \leqslant 160\) | \(160 < x \leqslant 170\) |
| Frequency | 25 | 29 | 24 | 18 | 4 |
- Estimate the number of boys who have heights of at least 155 cm .
- Calculate an estimate of the median height of the 100 boys.
- Draw a histogram to illustrate the data.
The histogram below shows the heights of 100 girls in Year 7 at the same school.
\includegraphics[max width=\textwidth, alt={}, center]{ab4d5ab1-e3b7-495f-9142-d37df7e712de-1_868_1361_1015_381} - How many more girls than boys had heights exceeding 160 cm ?
- Calculate an estimate of the mean height of the 100 girls.