The table below shows the weekly profit in naira from a mini-market.

Weekly profit (N)	1-10	11-20	21-30	31-40	41-50	51-60
Freq	6	6	12	11	10	5

(a) Draw the cumulative frequency curve of the data;

(b) From your graph, estimate the :  (i) median ; (ii) 80th percentile

(c) What is the modal weekly profit?