| Date | May 2011 | Marks available | 1 | Reference code | 11M.1.sl.TZ1.14 |
| Level | SL only | Paper | 1 | Time zone | TZ1 |
| Command term | Write down | Question number | 14 | Adapted from | N/A |
Question
The weights in kg, of 80 adult males, were collected and are summarized in the box and whisker plot shown below.
Write down the median weight of the males.
Calculate the interquartile range.
Estimate the number of males who weigh between \(61\) kg and \(66\) kg.
Estimate the mean weight of the lightest \(40\) males.
Markscheme
\(61\) kg (A1) (C1)
[1 mark]
\(66 - 52\) (A1)
\( = 14\) (A1)(ft) (C2)
Note: Award (A1) for identifying quartiles, (A1)(ft) for correct subtraction of their quartiles.
[2 marks]
\(20\) (A1) (C1)
[1 marks]
\(\frac{{49.5 \times 20 + 56.5 \times 20}}{{40}}\) (M1)
Note: Award (M1) for multiplication of midpoints by frequencies.
\(= 53\) kg (A1) (C2)
[2 marks]
Examiners report
Question 14 parts a and b were well done.
Question 14 parts a and b were well done.
Parts c and d were omitted or incorrectly answered more frequently than any other question on the exam paper.
Parts c and d were omitted or incorrectly answered more frequently than any other question on the exam paper.
