X=1×0,05+2×0,18+3×0,23+4×0,41+5×0,13=3,39
(3,39)^2=1,4921
X^2=1^2×0,05+2^2×0,18+3^2×0,23+4^2×0,41+5^2×0,13=12,65
D=12,65-1,4921=11,1579
cигма=\/11,1579=3,34
