Porobability distribution of X x P(x) 0 0.2 1 0.4 2 0.4 Total .1.0 i] Expectation Mean=Σxp Variance=x²p-(∑xp)² thus: Mean=(0*0.2)+(1*0.4)+(2*0.4) =0+0.4+0.8 =1.2
ii] Variance Variance=[(0²*0.2)+(1²*0.4)+(2²*0.4)]-(1.2)² =[0+0.4+1.6]-1.44 =0.56 hence: standard deviation=sqrt(0.56)=0.74833