The mean and the variance 10 observations are given to be 4 and 2 respectively. If every observation is multiplied by 2, the mean and the variance of the new series will be respectively.

Options

A. 8 and 20
B. 8 and 4
C. 8 and 8
D. 80 and 40

Answer

C

Explanation

Mean `(barX)=4`
Variance `(X)=2`
Number of observation = 10
`"New average "=((4xx10)xx2)/(10)=8`
New variance `=(2)^(2)xx"Variance (X)"`
`=4xx2=8`
`therefore" Option (c) is correct."`