Question 1120593
The mean is the sum of all integers * their probability 
0+0.066+0.344+0.819
0.948+0.705+0.576=3.458 mean

variance is the sum of the difference between the integer and the mean * probability
3.458^2*0.015=0.1794
2.458^2*0.066=0.3988
1.458^2*0.172=0.3656
0.458^2*0.273=0.0573
0.542^2*0.237=0.0696
1.542^2*0.141=0.3353
2.542^2*0.096=0.6203
sum is 2.0263 variance

sd is sqrt (2.0263)=1.423  standard deviation