Marks Frequency Marks Frequency 1-10 11-20 21-30 6 49 51-60 44 61-70 29 71-80 13 31-40 41-50 70 65 81-90 7 91-100 3 (a) Draw a cumulative frequency curve. (b) Use your graph to estimate: (1) the median (ii) the interquartile range (c) Pupils scoring 75marks or more were awarded distinctions. Estimate the number of pupils who had distinctions. (d) If a pupil is chosen, what is the probability that his marks will be greater than 65 marks?
