The probability that an African American person in the US has type O+ blood is 47%.
Four unrelated African Americans]are selected at random. Find the probability that all of the four have type O+ blood.
Since each person is selected at random, we assume that their blood type is independent of each other. Therefore, we can use the multiplication rule of independent events:
P(all four have O+ blood) = 0.47 x 0.47 x 0.47 x 0.47
P(all four have O+ blood) = 0.047^4
P(all four have O+ blood) = 0.00003468 or about 0.0035%
To find the probability that all four unrelated African Americans selected at random have type O+ blood, we need to multiply the probabilities of each individual having type O+ blood.
Given that the probability of an African American person in the US having type O+ blood is 47%, we can represent this probability as 0.47.
Since the four individuals are randomly selected and their blood types are independent, we can multiply the probabilities together:
P(all four have type O+ blood) = P(person 1 has type O+ blood) * P(person 2 has type O+ blood) * P(person 3 has type O+ blood) * P(person 4 has type O+ blood)
= 0.47 * 0.47 * 0.47 * 0.47
Calculating this probability:
P(all four have type O+ blood) = 0.47^4
P(all four have type O+ blood) = 0.1038234431
Therefore, the probability that all four randomly selected African Americans have type O+ blood is approximately 0.1038 or 10.38%.