Ok, we need to find the standard deviation for the distribution showed in the table, so let's do it:
[tex]\begin{gathered} standarddeviation\text{ = }\sigma \\ \sigma^2=2^2(0.2)+3^2(0.36)+4^2(0.31)+5^2(0.13)-3.37^2 \\ \sigma^2=0.8931 \\ \sigma=\sqrt[]{0.8931}\approx0.945 \end{gathered}[/tex]So, finally we get that the standar desviation is aproximately 0.945.
