The weekly wages of 31 factory workers are given in the table below, but the class intervals are listed in a random order.
Wages (₹): 30–40 10–20 50–60 20–30 40–50
Frequency: 6 5 4 9 7
(a) Rewrite the distribution with the class intervals in ascending order.
(b) Construct the cumulative frequency table for the reordered distribution.
(c) Determine the median weekly wage of the workers.