Question

The class size of a distribution is 25 and the first class-interval is 200-224. There are seven
class-intervals.
(i) Write the class-intervals.
(ii) Write the class-marks of each interval.

Answer 1

Given,
Class size = 25
First class interval =200-224

(i) Seven class intervals are:
200-240, 225-249, 250-274, 275-299, 300-324, 325-349, 350-374.

(ii) Class mark of `200-224=(200+224)/2=424/2=212`

    Class mark of `225-249=(225+249)/2=474/2=237`

    Class mark of `250-274=(250+274)/2=524/2=262`

    Class mark of `300-324=(300+324)/2=624/2=312`

    Class mark of `325-349=(325+349)/2=674/2=337`

   Class mark of `350-374=(350+374)/2=724/2=362`