Question

Marks :	Below 10	Below 20	Below 30	Below 40	Below 50
Number of Students :	3	12	27	57	75

For the above distribution, the modal class is :

• A. 45585
• B. 20-30
• C. 30-40
• D. 40-50

Answer 1

The Correct Option is C

Step 1: Understanding the given data:
We are given a cumulative frequency distribution table:

Marks:	Below 10	Below 20	Below 30	Below 40	Below 50
Number of Students:	3	12	27	57	75

Step 2: Finding the modal class:
The modal class is the class interval with the highest frequency. To determine this, we need to calculate the frequency for each class.
The frequency for each class interval can be calculated by subtracting the cumulative frequency of the previous class from the cumulative frequency of the current class:

Frequency for each class:
- Frequency for "Below 10" = 3 (since it's the first class, it is the cumulative frequency itself)
- Frequency for "10 to 19" = 12 - 3 = 9
- Frequency for "20 to 29" = 27 - 12 = 15
- Frequency for "30 to 39" = 57 - 27 = 30
- Frequency for "40 to 49" = 75 - 57 = 18

Step 3: Identifying the modal class:
The class with the highest frequency is "30 to 39" with a frequency of 30.
Thus, the modal class is **30 to 40** (rounded interval).

Step 4: Conclusion:
The modal class for the given distribution is **30-40**.