The frequency distribution of the weight of 100 participants in a high jump competition is as shown below :

Weight (kg)	20 - 29	30 - 39	40 - 49	50 - 59	60 - 69	70 - 79
Number of  Participants	10	18	22	25	16	9

(a) Construct the cumulative frequency table.

(b) Draw the cumulative frequency curve.

(c) From the curve, estimate the : (i) median ; (ii) semi- interquartile range ; (iii) probability that a participant chosen at random weighs at least 60 kg.