engineering recuitment AAI ATC Junior Executive 2025 Mock Test Series Mathematics Statistics Variance and Standard Deviation
The mean and the variance of 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.
1
8 and 20
2
8 and 4
3
8 and 8
4
80 and 40