Individuals who have a particular gene have a 060 probabilit

Individuals who have a particular gene have a 0.60 probability of contracting a certain disease. Suppose that 971 individuals with the gene participate in a lifetime study. What is the standard deviation of the number of people who eventually contract the disease?

Write only a number as your answer. Round to 2 decimal places

Solution

p=0.6

q = 1 - p

q = 1 - 0.6

q = 0.4

n = 971

sd = sqrt(npq)

sd = sqrt(971*0.6*0.4)

sd = 15.26