If the variance of 3+x, 6, 4, x and 7x is 4 and the mean is 5, find the standard deviation

A.
(sqrt{3}) 
B.
2 
C.
3 
D.
(sqrt{2})
Correct Answer: Option B
Explanation
Let (delta^2) and (delta) denote the variance and standard deviation of the distribution respectively.
But (delta^2) = 4 (given)
Hence (delta) = (sqrt{4}) = 2
There is an explanation video available below.