What is the class mark of class 21-30 in the table of Q.3 ?

Class Interval = 21 – 30 (given)


Upper class limit = 30


Lower class limit = 21


Class marks = 1/2 [upper limit + lower limit]


Class marks = 1/2 [30 + 21]


Class marks = 51/ 2 = 25.5

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