Foundation November 2023 Paper 2 Q10
10 Here are the salaries, in £, of the 6 workers in a company.
18 300 20 700 21 500 21 500 21 500 99 000
(a) Work out the mean salary. [2 marks]
(b) Why is the mean not the best average to represent the salaries? [1 mark]
| Answer | Mark | Comments |
|---|---|---|
| \((18\,300 + 20\,700 + 21\,500 + 21\,500 + 21\,500 + 99\,000) \div 6\) or \(202\,500 \div 6\) | M1 | oe allow missing brackets |
| 33 750 | A1 | SC1 120 000 or [30 166, 30 167] |
Additional guidance
| Correct answer followed by rounding eg 33 750 followed by 30 000 | M1A1 |
| Special cases are for missing brackets or omitting one 21 500 | |
| Addition signs between the numbers with an attempt at a total implies addition | |
| A vertical column of the 6 numbers with an attempt at a total implies addition | |
| Allow misreads but must be dividing by 6 | |
| Accept incorrect money notation for the mean eg1 33 750.0 eg2 30 166.6 | M1A1 SC1 |
| Answer | Mark | Comments |
|---|---|---|
| Valid explanation | B1 | accept any indication that one of the values is non-typical, or that the mean would be non-typical |
Additional guidance
| Ignore any attempt to state the best average | |
| Ignore irrelevant, non-contradictory statements | |
| Accept any indication that 99 000 is significantly different | |
| One is an outlier / anomaly / is an odd one out / doesn’t fit | B1 |
| The large value boosted the average | B1 |
| The average is too large | B1 |
| (Five are below / most are below and) only one is above the mean | B1 |
| Five are below / most are below (and only one is above) the mean | B1 |
| 99 000 / one number is much bigger | B1 |
| 99 000 / one number is bigger | B0 |
| The range is too large | B0 |
| The numbers are all different | B0 |
| Some numbers are much bigger | B0 |
| Some of the numbers are the same | B0 |
| It is an estimate / it’s not exact / it’s not accurate | B0 |