Q72Single correct3 Marks20 Nov 2022

Suppose iron rods are manufactured with a mean weight of $10$ kg and a standard deviation of $0.4$ kg. How does the variance of the sample mean change when the sample size is increased from $25$ to $64$?

A

Variance is increased from $0.0064$ to $0.0025$.

B

Variance is increased from $0.0025$ to $0.0064$.

C

Variance is reduced from $0.0064$ to $0.0025$.

D

Variance is reduced from $0.0025$ to $0.0064$.