Question 1118896
Let X be a random variable denoting the number of people having genetic mutation out of 300 people. X follows Binomial Distribution with parameters n = 300 and 
p = 0.03
The standard deviation of X is:
sqrt(n*p*(1-p)) = sqrt(300*0.03*(1-0.03)) = 8.73 = sqrt 8.73 = 2.955