A company is investigating how long it takes employees, t t\,t minutes, to get to an event. They produce a table below of coded times, x x\,x minutes, for a random sample of 50 employees.
| Coded Time (minutes) | Frequency |
|---|---|
| 0<x≤50 < x \leq 50<x≤5 | 1 |
| 5<x≤105 < x \leq 105<x≤10 | 9 |
| 10<x≤1510 < x \leq 1510<x≤15 | 19 |
| 15<x≤2515 < x \leq 2515<x≤25 | 14 |
| 25<x≤4025 < x \leq 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 data was calculated using the formula: x=t−202\displaystyle x = \frac{t - 20}{2}x=2t−20
Calculate the median and the standard deviation of ttt.
Practise Edexcel A Level Maths Measures of Location and Spread with exam-style questions for A Level Maths. 7 questions covering 2.1 Measures of Central Tendency, 2.2 Other Measures of Location, 2.3 Measures of Spread, 2.4 Variance and Standard Deviation, and 2.5 Coding, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
