Higher November 2020 Paper 1R Q4
4 The table gives information about the length of time, in minutes, that each of 60 students took to travel to school on Monday.
| Length of time (\(t\) minutes) | Frequency |
|---|---|
| \(0 \lt t \leqslant 10\) | 4 |
| \(10 \lt t \leqslant 20\) | 10 |
| \(20 \lt t \leqslant 30\) | 15 |
| \(30 \lt t \leqslant 40\) | 25 |
| \(40 \lt t \leqslant 50\) | 6 |
(a) Write down the modal class interval. (1)
(b) Work out an estimate for the mean length of time taken by these 60 students to travel to school on Monday.
Give your answer correct to one decimal place. (4)
Give your answer correct to one decimal place. (4)
| Scheme | Marks |
|---|---|
| \(30 \lt t \leqslant 40\) | B1 |
| (1) |
| Scheme | Marks |
|---|---|
| e.g. 5 × 4 + 15 × 10 + 25 × 15 + 35 × 25 + 45 × 6 (= 1690) or 20 + 150 + 375 + 875 + 270 (= 1690) | M2 |
| “1690” ÷ 60 | M1 |
| 28.2 | A1 |
| (4) | |
| (5 marks) |
Notes
M2: For correct products using midpoints (allowing one error) with intention to add.
If not M2 then award M1 for products using frequency and a consistent value within the range (allowing one error) with intention to add or correct products using midpoint without addition.
M1: dep on M1
A1: accept 28.1 – 28.2