The distance travelled by 100 people to an event is summarised 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=2651\sum fx=2651∑fx=2651 and ∑fx2=80434.25\sum fx^2=80434.25∑fx2=80434.25.
Use linear interpolation to estimate the median height.
Estimate the mean height.
Estimate the standard deviation.
4 exam-style questions on Edexcel A Level Maths 2.4 Variance and Standard Deviation. Each one has a worked solution and a mark scheme showing where the marks go.