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Asked by suchet_r | 11th Aug, 2009, 07:59: PM

Expert Answer:

Summation of all frequencies is 50. Hence,

5 + f1 + 10 + f2 + 7 + 8  = 50

f1 + f2 = 20 ........(1)

Mean of the frequency distribution = [summation of ( class mean x frequency) for each class]/frequency total

The class mean for 0-20 is 10, 20-40 is 30 and so on.

Hence,

(10x5 + 30xf1 + 50x10 + 70xf2 + 90x7 + 110x8)/50 = 62.8

30f1 + 70f2 = 1080 ........(2)

Solving (1) and (2)

we find, f1 = 8 ;    f2 = 12

Regards,

Team,

TopperLearning.

 

 

Answered by  | 11th Aug, 2009, 10:17: PM

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