Question 1186284
E(X)=mean = x*p(x) all summed
this is 0.45+0.30+2.25, multiplying the 3 rows. They add to 3, the mean, which can be seen also by the symmetry of the distribution.
sd is sqrt sum of  (square differences)(probability)/n
=4*0.45+0*0.10+4*0.45
=3.60
sqrt (3.60)=1.90