SOLUTION: 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 dis

Algebra ->  Probability-and-statistics -> SOLUTION: 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 dis      Log On


   



Question 1190870: 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 U.S. probability
A 0.42
B 0.11
AB 0.03
O ?
a)What is the probability of type O blood in the United States?
b)Sasha has type A blood. She can safely receive blood transfusions from people with blood types O and A. What is the probability that a randomly chosen person from the United States can donate blood to Sasha? (This exercise and the one that follows ignore the Rh factor, another classification of blood types that is related to whether one person can donate blood to another.)

Answer by math_tutor2020(3817) About Me  (Show Source):
You can put this solution on YOUR website!

Part (a)

Original Table
Blood typeU.S. probability
A0.42
B0.11
AB0.03
O?

With any probability distribution, we need to have the following
  • Every P(X) value is between 0 and 1, ie
  • All of the P(X) values add to 1 so that we account for 100% of every event possible.
Let m be the missing probability in the table
It must add with the other probabilities to get to 1.
0.42+0.11+0.03+m = 1
0.56+m = 1
m = 1-0.56
m = 0.44
This tells us that 44% of patients in the US have type O blood.

This is what the table looks like with the missing item filled in properly
Blood typeU.S. probability
A0.42
B0.11
AB0.03
O0.44

I'll let you check the two requirements I mentioned earlier.

Answer: 0.44

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Part (b)

Add up the probabilities for type O and type A blood
0.42+0.44 = 0.86

Answer: 0.86