The table shows the frequency distribution of marks scored by some candidates in an examination. Marks 0-9 10-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 9...

Question 1 Report

The table shows the frequency distribution of marks scored by some candidates in an examination.

Marks 0-9 10-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 90-99
Freq 2 5 8 18 20 15 5 4 2 1

(a) Draw the cumulative frequency curve of the distribution.

(b) Use your graph to estimate the :

(i) semi-interquartile range of the distribution; (ii) percentage of candidates who passed with distinction if the least mark for distinction was 72.