The following grouped data show the heights of 50 saplings in a botanical garden.
Class interval (cm): 20–30 | 30–40 | 40–50 | 50–60 | 60–70
Frequency: 3 | 8 | 15 | 17 | 7
Answer the following questions based on the distribution.
(i) Prepare a ‘less than’ cumulative frequency column for the given data.
(ii) Identify the median class and give a brief reason for your choice.
(iii) Explain how cumulative frequency helps in locating the median class for any grouped data set.