a. The table shows the scores of 2000 candidates in an entrance examination into a private secondary school.

% mark	11 - 20	21 - 30	31 - 40	41 - 50	51 - 60	61 - 70	71 - 80	81-90
Number of pupils	68	184	294	402	480	310	164	98

Prepare a cumulative frequency table and draw the cumulative frequency curve for the distribution.

bi. Use the curve to estimate the cut-off mark if 300 candidates are to be offered admission.

bii. Use your curve to estimate the probability that a candidate picked at random scored at least 45%