The mean of four observations is 3 . If the sum of the squares of these observations is 48 , then their standard deviation is

Step-by-step solution

Let four observations are be x₁, x₂, x₃ and x₄ Given, mean and aligned ( x ) & =3 x_i^2 & =48 aligned aligned SD & = x_i^2 n -( x )^2 = 48 4 -(3)^2 = 12-9 & = 3 aligned