The distances travelled by 100 people to an event, recorded to the nearest mile, are summarised in the table below.
| Distance (nearest mile) | Frequency |
|---|---|
| 0–9 | 4 |
| 10–19 | 19 |
| 20–29 | 41 |
| 30–39 | 26 |
| 40–49 | 9 |
| 50–59 | 1 |
You may use ∑fx=2650\sum fx = 2650∑fx=2650 and ∑fx2=80 425\sum fx^2 = 80\,425∑fx2=80425, where the values of x x\,x are the class midpoints.
Use linear interpolation to estimate the median distance.
Estimate the mean distance.
Estimate the standard deviation of the distances.