A company is investigating how long it takes employees, t t\,t minutes, to get to an event. The table below gives the coded times, x x\,x minutes, for a random sample of 50 employees.
| Coded time (minutes) | Frequency |
|---|---|
| 0<x≤50 < x \le 50<x≤5 | 1 |
| 5<x≤105 < x \le 105<x≤10 | 9 |
| 10<x≤1510 < x \le 1510<x≤15 | 19 |
| 15<x≤2515 < x \le 2515<x≤25 | 14 |
| 25<x≤4025 < x \le 4025<x≤40 | 7 |
Use linear interpolation to estimate the median of the coded times.
Estimate the standard deviation of the coded times.
The coded times were obtained using x=t−202\displaystyle x = \frac{t - 20}{2}x=2t−20. Estimate the median and the standard deviation of ttt.
105 exam-style questions on WJEC A Level Maths 2.2 Data presentation and interpretation, covering 2.2.1 Data presentation and interpretation, 2.2.2 Data presentation and interpretation, 2.2.3 Data presentation and interpretation, 2.2.4 Data presentation and interpretation, 2.2.5 Data presentation and interpretation, 2.2.6 Data presentation and interpretation, 2.2.7 Data presentation and interpretation, 2.2.8 Data presentation and interpretation, and 2.2 Data presentation and interpretation. Each one has a worked solution and a mark scheme showing where the marks go.