Foundation June 2017 Paper 2 Q20
20 George is the manager of a shoe shop.
He samples 50 of his customers and asks them about the one style of shoe they would buy next.
The table shows his results.
| Style of shoe | Number of customers |
|---|---|
| Laced shoes | 18 |
| Boots | 15 |
| Sandals | 8 |
| Trainers | 5 |
| Other | 4 |
George buys 1000 pairs of shoes with the number of each style based on his survey results.
How many pairs of sandals should he buy?
Write down any assumption you make about his sample. [3]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 160 and assumed that sample of 50 is representative oe | 3 | B2 for 160 or M1 for \(\dfrac{8}{50} \times 1000\) oe AND B1 for assumed that sample of 50 is representative oe | Accept: Representative, not biased, random Ignore extra comments after correct comment given SEE APPENDIX B |
Appendix B
Answer should refer to sample and imply the sample asked was random/representative
Accept answers that refer to the proportions for 1000 being the same as the sample oe
Exemplar responses for Q20
| Response | Mark |
|---|---|
| Assume he asked males and females Implies sample should be representative | 1 |
| He did not just ask one age group Implies sample should be representative | 1 |
| His sample is random | 1 |
| The sample is reliable for other customers | 1 |
| He used stratified sampling meaning it was in proportion | 1 |
| It stays in the same proportion | 1 |
| Assuming the other people say the same | 1 |
| Everyone has the same style as the people in the survey | 1 |
| I assume that the trend in his table would carry on for the next 1000 shoes. | 1 |
| I made the assumption that his other customers buy the same as the customers he sampled | 1 |
| 50 customers represent the same as what 1000 customers want | 1 |
| For every 50 customers the variation is constant | BOD1 |
| I assumed the number of people choosing sandals would remain the same | BOD1 |
| He asked his consistent regular reliable customers | BOD 1 |
| He only asked people visiting the shoe shop to answer his survey This does not address the sample issue – they are all his customers | 0 |
| Because for every customer’s choice 20 pairs should be bought. | 0 |
| He only sampled 50 people so the results might not be accurate. | 0 |
| The same customers came in | 0 |