| Date | November 2012 | Marks available | 2 | Reference code | 12N.1.sl.TZ0.5 |
| Level | SL only | Paper | 1 | Time zone | TZ0 |
| Command term | Find | Question number | 5 | Adapted from | N/A |
Question
The cumulative frequency curve shows the percentage marks, given correct to the nearest integer, gained by 500 students in an examination.
The passing grades were determined as given below.
85 to 100 %, grade A
66 to 84 %, grade B
57 to 65 %, grade C
50 to 56 %, grade D
Those scoring less than 50 % failed the examination.
Find the number of students who failed the examination.
Find the number of students who were awarded grade C or better.
The top 20 % of the students are eligible for further study.
Find the lowest mark required to be eligible for further study.
Markscheme
200 (students) (M1)(A1) (C2)
Note: Award (M1) for line drawn on the graph connecting 50 % with 200 or any indication (cross or dash) at the required point on the graph, (A1) for correct answer.
[2 marks]
500 – 350 (M1)
Notes: Award (M1) for 350 seen or for a line on the graph from 57 % up to the curve showing number of students. An indication (cross or dash) at the required point on the graph is sufficient for method.
= 150 (A1) (C2)
[2 marks]
60 (%) (M1)(A1) (C2)
Notes: Award (M1) for 400 or a line on the graph at 400 seen, (A1) for correct answer. % sign not required. An indication (cross or dash) at the required point on the graph is sufficient for method.
[2 marks]
Examiners report
Candidates who drew vertical or horizontal lines at correct positions on the graph were able to pick up the three method marks for this question and, for parts (a) and (b), a range of answers were accepted. The most common error on this question seemed to be in part (a) where the vertical line was drawn at 49% leading to a value outside the acceptable range of 190–200. Candidates are expected to read values off a continuous cumulative frequency curve at the given critical values (in this instance at 50%).
There was a mistake in the Spanish translation of question 5, which was discovered prior to marking. The principal examiner was informed and this unfortunate situation was addressed during the marking and awarding in order to ensure no candidate was disadvantaged.
Candidates who drew vertical or horizontal lines at correct positions on the graph were able to pick up the three method marks for this question and, for parts (a) and (b), a range of answers were accepted. In part (b), a common incorrect answer seen was 350 which was simply the number of candidates who were awarded less than a grade C rather than those with a grade C or higher. On a minority of scripts, an answer of 90 reflected the candidate's misinterpretation of the requirement of the question as 'grade C only'.
There was a mistake in the Spanish translation of question 5, which was discovered prior to marking. The principal examiner was informed and this unfortunate situation was addressed during the marking and awarding in order to ensure no candidate was disadvantaged.
Candidates who drew vertical or horizontal lines at correct positions on the graph were able to pick up the three method marks for this question and, for parts (a) and (b), a range of answers were accepted. In part (c), a numerical answer of 60 was required, with 'grade C' on its own losing this last mark.
There was a mistake in the Spanish translation of question 5, which was discovered prior to marking. The principal examiner was informed and this unfortunate situation was addressed during the marking and awarding in order to ensure no candidate was disadvantaged.
