The lengths of 40 leaves of a plant are measured correct to the nearest millimeter, and the data obtained is represented in the following table:
Length (in mm): | 118-126 | 127-135 | 136-144 | 14 5-153 | 154-162 | 163-171 | 172-180 |
No. of leaves: | 3 | 5 | 9 | 12 | 5 | 4 | 2 |
Find the median life.
: The given data is not having continuous class intervals. So, we have to add and subtract 0.5 to upper class limit and lower class limit.
Length (in mm) | Number of leaves | Cumulative frequency |
117.5-126.5 | 3 | 3 |
126.5-135.5 | 5 | 8 = 3 + 5 |
135.5-144.5 | 9 | 17 = 8 + 9 |
144.5-153.5 | 12 | 29 = 17 + 12 |
153.5-162.5 | 5 | 34 = 29 + 5 |
162.5-171.5 | 4 | 38 = 34 + 4 |
171.5-180.5 | 2 | 40 = 38 + 2 |
Median class = 144.5-153.5
l = 144.5, h = 9, f = 12 and F = 17
Median = l + 
* h
= 144.5 + (
* 9
= 144.5 + 
= 146.75
So, median length is 146.75 mm.
17