Foundation June 2017 Paper 2 Q11
11. Sharifa keeps a record of the number of phone calls she makes each day.
These are her results for one week.
7 9 6 3 7 9 6
(a) Why is the mode not suitable to use as the average number of calls made each day? [1]
(b)
Work out the range, and the median number of calls made each day. [2]
Range ……………… Median ………………
(c)
When Sharifa does not include the calls made on Saturday and Sunday, the new range is 4.
(i) How many calls were made on Saturday? [1]
(ii) What impact does this have on the median? [1]
| Scheme | Marks | Comments |
|---|---|---|
| Explaining that there is no mode. e.g. ‘no number appears more than the others’ ‘there is more than one mode’ | E1 | Allow explanations that consider the mode such as ‘there are two 6s, 7s and 9s’. |
| Scheme | Marks | Comments |
|---|---|---|
| (range =) 6 | B1 | |
| (median =) 7 | B1 |
| Scheme | Marks | Comments |
|---|---|---|
| (i) 9 | B1 | |
| (ii) explanation e.g. ‘the median would be reduced’ | E1 | Allow calculation e.g. ‘the median would become 6’ or equivalent. FT ‘their median’ from (b) Do not allow ‘it changes’ or equivalent. |
| (5) |
Corrected by Westie's Workshop
- The board's mark scheme printed “from (a)”. Changed to “from (b)” because the median is worked out in part (b); part (a) is about the mode.
Original: see the board's mark scheme PDF (link above).