Sarah is recording the weights, in kg, of the luggage for passengers on a flight.
| Weight (w w\,w kg) | Frequency |
|---|---|
| 0<w≤100 < w \leq 100<w≤10 | 8 |
| 10<w≤1510 < w \leq 1510<w≤15 | 12 |
| 15<w≤2015 < w \leq 2015<w≤20 | 18 |
| 20<w≤2520 < w \leq 2520<w≤25 | 15 |
| 25<w≤3525 < w \leq 3525<w≤35 | 7 |
Estimate the mean weight of the luggage. Give your answer correct to 1 decimal place.
Explain why your answer to part (a) is an estimate.