| Date | May 2012 | Marks available | 2 | Reference code | 12M.1.sl.TZ1.5 |
| Level | SL only | Paper | 1 | Time zone | TZ1 |
| Command term | Find | Question number | 5 | Adapted from | N/A |
Question
The daily rainfall for the town of St. Anna is collected over a 20-day period of time. The collected data are represented in the box and whisker plot below.
Write down
(i) the lowest daily rainfall;
(ii) the highest daily rainfall.
State what the value of 12 mm represents on the given diagram.
Find the interquartile range.
Write down the percentage of the data which is less than the upper quartile.
Markscheme
(i) 6 (mm) (A1)
(ii) 20 (mm) (A1) (C2)
[2 marks]
Median (A1) (C1)
Note: Award (A1) for Q2 or 50th percentile.
[1 mark]
14 – 9 (A1)
Note: Award (A1) for 9 and 14 seen.
5 (mm) (A1) (C2)
[2 marks]
75 (%) (A1) (C1)
[1 mark]
Examiners report
Parts (a) and (b) proved to be very well done with many correct answers seen. On a few scripts however, candidates who seemed unsure of the correct average, wrote down, average, mean or even medium.
Parts (a) and (b) proved to be very well done with many correct answers seen. On a few scripts however, candidates who seemed unsure of the correct average, wrote down, average, mean or even medium.
Part (c) was generally well done with many candidates correctly identifying Q1 and Q3 and many correct answers of 5 were seen.
75% proved to be an elusive answer on many scripts for part (d) as a significant number of candidates did not seem to understand the meaning of quartiles. Indeed, a popular, but erroneous answer seen was 57.1% which was arrived at from the calculation \(\frac{{14 - 6}}{{14}} \times 100\).
