Mathematics WAEC / WASSCE 1993 Statistics and Probability
The table below shows the frequency distribution of the marks scored by fifty students 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 3 4 6 13 10 5 3 2 2 (a) Draw the cumulative frequency curve for the distribution. (b) Use your curve to estimate the : (i) upper quartile; (ii) pass mark if 60% of the students passed.