Class |
Frequency (f) |
Cumulative frequency (c.f.) |
10-20 |
1 |
1 |
20-30 |
3 |
4 |
30-40 |
5 |
9 |
40-50 |
9 |
18 |
50-60 |
7 |
25 |
60-70 |
3 |
28 |
Median = \(\frac N 2\)th term
\(= \frac{28}2\)
= 14th term
∴ Median class = 40-50
So the lower limit of the median class = 40
Modal class is the class interval with the highest frequency in the frequency table.
Therefore we have, maximum frequency = 9
So, modal class = 40-50
then the upper limit = 50
The sum of lower limit of the median class + the upper limit of the modal class
= 40 + 50
= 90
Hence, 90 is the sum of lower limit of the median class and the upper limit of the modal class.