Mean or Expected Value and Standard Deviation · Exercise 3

Find the standard deviation.

\begin{array}{|c|c|c|c|}\hline \text{x} & \text{P(x)} & \text{x*P(x)} & \text{(x – μ)^2P(x)} \\ \hline \text{2} & \text{0.1} & \text{2(.1) =.2} & \text{(2–5.4)^2(.1) = 1.156} \\ \hline \text{4} & \text{0.3} & \text{4(.3) = 1.2} & \text{(4–5.4)^2(.3) =.588} \\ \hline \text{6} & \text{0.4} & \text{6(.4) = 2.4} & \text{(6–5.4)^2(.4) =.144} \\ \hline \text{8} & \text{0.2} & \text{8(.2) = 1.6} & \text{(8–5.4)^2(.2) = 1.352} \\ \hline\end{array}

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Statistics · §4.2 Mean or Expected Value and Standard Deviation · Exercise 3