Rh blood types. Human blood is typed as O, A, B, or AB and also as Rh-positive or Rh-negative. ABO type and Rh-factor type are independent because they are governed by different genes. In the American population, 84% of people are Rh-positive. Use the information about ABO type in given Exercise to give the probability distribution of blood type (ABO and Rh) for a randomly chosen person.
Exercise
Distribution of blood types. All human blood can be "ABO-typed" as one of O, A, B, or AB, but the distribution of the types varies a bit among groups of people. Here is the distribution of blood types for a randomly chosen person in the United States
|
Blood Type
|
A
|
B
|
AB
|
O
|
|
U.S. Probability
|
0.42
|
0.11
|
?
|
0.44
|
(a) What is the probability of type AB blood in the United States?
(b) Maria has type B blood. She can safely receive blood transfusions from people with blood types O and B. What is the probability that a randomly chosen person from the United States can donate blood to Maria?