Question 1150212
binomial with n=30 and p=0.3
probability 0 are short sighted is 0.7^30
probability 1 is short sighted is 30*0.7^29*0.3, The 30 being the number of different ways
probability of 2 is 30C2*0.7^28*0.3^2
first is 0.00002
second is 0.0003
third is 0.0018
the probability is 0.0021. Table shows the same.

expected value is 6
variance is 4.2 sd is 2.05