Is there a way to define as a new operator the mathematical expectation.
Say we call it M as in the old Mir (russian books).
Wa should have
$\mathrm{M}(kX) = k\mathrm{M}(X)$
M(X±Y)=M(X)±M(Y)
and as a résult
M(X−MX)2=M(X2)−M(X)2
$\mathrm{M}(aX^2 +bX + c) = a\mathrm{M}(X^2) +b\mathrm{M}(X) + c$
and so on for all polynomial ?