The following unsorted grouped data show the marks (out of 50) obtained by 50 students in a test:
Class interval (marks): 30–40 | 10–20 | 40–50 | 20–30 | 0–10
Frequency: 8 | 12 | 6 | 14 | 10
(i) Arrange the class intervals in ascending order.
(ii) Construct the ‘less than’ cumulative frequency table for the ordered classes.
(iii) Identify the median class for the distribution.