If `x_(1),x_(2)……..x_(n)` be n observation and `barx` be their arithmetic mean .Then formula of the standard deviation is given by
A. Standard deviation for `2x,2x_(2),2x_(3)`…….`2x_(n)` is `sqrt(2)sigma`
B. Standard deviation for `2+x_(1),2+x_(2),2+x_(3),….2+x_(n)` is `2+sigma`
C. Variance `3x_(1),3x_(2),3x_(3),…,2x_(n)` is `9sigma^(2)`
D. Mean of `5+x_(1),5+x_(2),5+x_(3)…,5+x_(1)` is `bar(x)`
