Question

What is the class mark of the class interval-(80-90)?

• A. 82.5
• B. 90
• C. 80
• D. 85

Answer 1

The correct option is D 85

To calculate the mean of a continuous series, mid points of the various class intervals is taken before calculating the mean which is also called the class mark. For example, if the class interval is 80-90 then before calculating the mean mid point that is the class mark is calculated which is 85.