Question

The outcome of each of 30 items was observed ; 10 items gave outcome 1/2  each and the remaining 10 items gave outcome 1/2 + d each.  If the variance of this outcome data is 4/3  then |d| equals :

(1) 2/3

(2) √5/2

(3) √2

(4) 2

Answer 1

The correct option is (3).

Explanation:

Variance is independent of shift of origin i.e. var. (x + b) = var.x

so we shift the given data by 1/2.