The probability of not-4 to occur is:
P(not 4)=1-P(4)=1-3/10=7/10
The probability of one of {1, 2, 3, 5, 6} to happen is
P(1)+P(2)+P(3)+P(5)+P(6) = P(not 4) =7/10
since all non-4 numbers have an equal chance to occur:
P(1)=P(2)=P(3)=P(5)=P(6)=(7/10)/5=7/50=0.14
Thus the expected value is :
1*P(1)+2*P(2)+3*P(3)+5*P(5)+6*P(6)+4*P(4)
=(1+2+3+5+6)*0.14+4*0.3=2.38+1.2=3.58
Answer: 3.58
