(Extra credit) All human blood can be typed as one of O, A, B, or AB. The distribution of the type varies a bit with race. For African-Americans, here are the approximate probabilities that a person will have blood type O, A, B, or AB. Blood Type O A B AB Probability 0.4 0.2 0.32 0.08 In a group of 10 randomly chosen people, what is the probability that two or more of them have Type A blood

Probability that two or more of them have Type A blood is 0.6242.

Step-by-step explanation:

We are given the approximate probabilities that a person will have blood type O, A, B, or AB.

Blood Type    O       A         B         AB

Probability    0.4    0.2      0.32    0.08

A group of 10 people are chosen randomly.

The above situation can be represented through Binomial distribution;

where, n = number of trials (samples) taken = 10 people

            r = number of success = two or more have Type A blood

           p = probability of success which in our question is probability

                that a person has Type A Blood, i.e; p = 20% or 0.20

LET X = Number of person having Type A Blood

So, it means X ~ Binom(n = 10, p = 0.20)

Now, Probability that two or more of them have Type A blood is given by = P(X 2)

  P(X 2)  =  1 - P(X = 0) - P(X = 1)

                 =  

                 =                 

                 =  0.6242

Hence, the probability that two or more of them have Type A blood is 0.6242.

answer: 1 + 1 = 11

step-by-step explanation: