According to data from the state blood program, 40 percent of all individuals have group A blood. If six individuals give blood, find the probability that none of the individuals has group A blood.
Multiple Choice
0410
0041
0427
4000
The correct answer and explanation is:
The problem involves finding the probability that none of the six individuals who give blood have group A blood. We are given that 40 percent of all individuals have group A blood, so the probability that an individual does not have group A blood is: P(not A)=1−P(A)=1−0.40=0.60P(\text{not A}) = 1 – P(\text{A}) = 1 – 0.40 = 0.60
This is the probability that a single individual does not have group A blood.
Since the six individuals are assumed to be independent (the blood type of one individual does not affect the others), the probability that all six individuals do not have group A blood is the product of the individual probabilities: P(none has group A)=(0.60)6P(\text{none has group A}) = (0.60)^6
Now, calculate this value: (0.60)6=0.046656(0.60)^6 = 0.046656
Therefore, the probability that none of the six individuals has group A blood is approximately 0.0467, or 4.67%. The correct answer is 0041.
This problem demonstrates the concept of independent events in probability, where the outcome of each event (in this case, each person’s blood type) is unaffected by the others. The result is computed by multiplying the probability of the individual event (not having group A blood) by itself for each of the six individuals.