Question

Plz need answer fast statistics class 10

Answer 1

Solution :-

Given data :

Class Intervals (CI):

10-25, 25-40,40-55,55-70,70-85,85-100

Frequencies (fi) :

2,3,7,r,5,6

Mid values (xi) :-

(10+25)/2 = 35/2 = 17.5

17.5, 32.5,47.5,62.5,77.5,92.5

fixi :-

35, 97.5,332.5,62.5r,387.5,555

Σfi = 23+r

Σfixi = 1407.5+62.5r

Mean = 62

We know that

Mean = Σfixi / Σ fi

=> 62 = (1407.5+62.5r)/(23+r)

=> 1407.5+62.5r = 62(23+r)

=> 1407.5+62.5r = 62r+1426

=> 1426-1407.5 = 62.5r-62r

=> 0.5r = 18.5

=> r = 18.5/0.5

=> r = 185/5

=> r = 37

The value of r = 37