Calculate the $EY$ and $DY$ if $Y=3(X-1)^2$. As I understand, $EY$ is calculated the same way $EX$ would be, only in this case first the value of a function must be calculated where $X$ denotes random variables. So, $EY=3\cdot 0.3 + 3 \cdot 0.1 + 12 \cdot = 1,92.$ But I have a problem with $DY$. The formula given is $$D(X)=M\left[ (X-M(X))^2 \right]=M((X-1,92)^2)=0.3 \cdot 3.69+0.1\cdot 0.64 + 0.6 \cdot 1.17= 0.12+0.06+0.7=0.25$$
It seems like a really small value, so I assume it's wrong. Can someone help?