Correct Answer - Option 4 : 25
Concept:
-
The cumulative frequency is calculated by adding each frequency from a frequency distribution table to the sum of its predecessors.
- To find out the median class you have to find the value of N/2 and then find out the interval in which it lies, where N is the final cumulative frequency.
-
The modal class is the group with the highest frequency.
Calculation:
Class |
Frequency |
Cumulative Frequency |
0-5 |
10 |
10 |
5-10 |
15 |
25 |
10-15 |
12 |
37 |
15-20 |
20 |
57 |
20-25 |
9 |
66 |
Here, N = 66
∴ N/2 = 33, which lies in the class interval 10-15.
So, the lower limit of the median class is 10.
Here, the highest frequency is 20, which lies in the class interval 15-20.
So, the lower limit of the modal class is 15.
So, the required sum is 10 + 15 = 25.
Hence, the sum of lower limits of the median class and modal class is 25.