5. In a shopping survey a random sample of 104 teenagers were asked how many hours, to the nearest hour, they spent shopping in the last month. The results are summarised in the table below.
| Number of hours | Mid-point | Frequency |
| 0-5 | 2.75 | 20 |
| 6-7 | 6.5 | 16 |
| 8-10 | 9 | 18 |
| 11-15 | 13 | 25 |
| 16-25 | 20.5 | 15 |
| 26-50 | 38 | 10 |
A histogram was drawn and the group ( \(8 - 10\) ) hours was represented by a rectangle that was 1.5 cm wide and 3 cm high.
- Calculate the width and height of the rectangle representing the group (16-25) hours.
- Use linear interpolation to estimate the median and interquartile range.
- Estimate the mean and standard deviation of the number of hours spent shopping.
- State, giving a reason, the skewness of these data.
- State, giving a reason, which average and measure of dispersion you would recommend to use to summarise these data.