In the small town,a certain type of Blu-ray player is sold at just two stores.33% of the sales are from store A and 67% of the sales are from store B.2.8% of the Blu-ray players sold at store A are defective while 3.7% of the Blu-ray players sold at store B are defective.If Kate receives one of these Blu-ray players as a gift and finds that it is defective,what is the probability that it came from store A?
A)0.373
B)0.028
C)0.33
D)0.728
E)0.272

Question

Quizplus · Accepted Answer

To find the probability that Kate's defective Blu-ray player came from store A, we use Bayes' theorem. The probability of a Blu-ray player being defective and from store A is (0.33 * 0.028), and the total probability of getting a defective Blu-ray player is (0.33 * 0.028) + (0.67 * 0.037). The probability that the defective Blu-ray came from store A is therefore (0.33 * 0.028) / [(0.33 * 0.028) + (0.67 * 0.037)] = 0.272.

In the Small Town,a Certain Type of Blu-Ray Player Is