Suppose individuals with a certain gene have a 0.70 probability of eventually contracting a certain disease. If 100 individuals with the gene are randomly selected. The random variable describing the number of individuals who will contract the disease is:

B(0.7, 100)

Step-by-step explanation:

Probability of contracting a certain disease = 0.70

No of individual randomly selected = 100

Contracting the disease is a positive/success in this case, hence

p = 0.7 and since there are 100 selection, the binomial distribution B(0.7, 100)

Hence, the The random variable describing the number of individuals who will contract the disease is B(0.7, 100) distribution.

And Mean = 0.7 x 100 = 70