Question

In a frequency distribution, the mid-value of a class is 15 and the class intervals is 4. The lower limit of the class is

(a) 10

(b) 12

(c) 13

(d) 14

Answer 1

Let l and m respectively be the lower and upper limits of the class. Then the mid-value of the class is and the class-size is.

Therefore, we have two equations

Subtracting the second equation from the first equation, we have

Hence, the lower limit of the class is 13. Thus, the correct choice is (c).