5. A teacher selects a random sample of 56 students and records, to the nearest hour, the time spent watching television in a particular week.
| Hours | \(1 - 10\) | \(11 - 20\) | \(21 - 25\) | \(26 - 30\) | \(31 - 40\) | \(41 - 59\) |
| Frequency | 6 | 15 | 11 | 13 | 8 | 3 |
| Mid-point | 5.5 | 15.5 | | 28 | | 50 |
- Find the mid-points of the 21-25 hour and 31-40 hour groups.
A histogram was drawn to represent these data. The \(11 - 20\) group was represented by a bar of width 4 cm and height 6 cm .
- Find the width and height of the 26-30 group.
- Estimate the mean and standard deviation of the time spent watching television by these students.
- Use linear interpolation to estimate the median length of time spent watching television by these students.
The teacher estimated the lower quartile and the upper quartile of the time spent watching television to be 15.8 and 29.3 respectively.
- State, giving a reason, the skewness of these data.