Question

if the probability that a person has blood type o is 0.35 and you have 40 randomly selectedpeople, about how many would you expect to have blood type o ? what is the standard deviationof the number of people who would have blood type o among the 40 people?

Answer 1

expected number of blood type o is 14, standard deviation is about 3.0166

Explanation:

we can see the data follows a binomial distribution. Two outcomes either o type or not

Expected Value( blood type o) = np

= 40*0.35 = 14

Variance = np(1-p)

Variance = 40*0.35*(1-0.35)

Variance= 40*0.35*0.65

Variance= 9.1

Standard deviation = sqrt(9.1) = 3.0166