4MA0 Foundation January 2013 Paper 2 Q18
18 The table shows information about the marks of 20 students in a science test.
| Mark | Frequency |
|---|---|
| 6 | 2 |
| 7 | 4 |
| 8 | 5 |
| 9 | 8 |
| 10 | 1 |
Work out the mean mark of the 20 students.
(3)
| Scheme | Marks |
|---|---|
| \(6 \times 2 + 7 \times 4 + 8 \times 5 + 9 \times 8 + 10 \times 1\) or \(12 + 28 + 40 + 72 + 10\) or 162 | M1 |
| “162” ÷ 20 | M1 (dep) |
| 8.1 | A1 |
| (3) |
Notes
M1: for at least 3 correct products and summing them
M1 (dep): for division by 20
A1: Accept 8 if \(162 \div 20\) seen
NB: Award A0 if 8.1 clearly comes from incorrect figures