Steven G
Elite Member
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- Dec 30, 2014
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A hospital receives 1/5 of its flu vaccine shipments from Company X and the remainder of its shipments from other companies. Each shipment contains a very large number of vaccine vials. For Company Xs shipments, 10% of the vials are ineffective. For every other company, 2% of the vials are ineffective. The hospital test 30 randomly chosen vials from a shipment and finds that one vial is ineffective. What is the probability that this shipment came from Company X?
I was hoping that someone can check my work
WOLOG we can assume that the other companies is just company Y
Keeping with the 1:4 ratio we can assume that 20 vials came from X and 80 came from Y
Then 2 ineffective vials are from X and 1.6 came from Y
Then P(an ineffective vial came from X) = 2/3.6 = 10/18 = 5/9
Then P(that this shipment came from Company X) = 30C1(5/9)1(4/9)29
Thank you.
I was hoping that someone can check my work
WOLOG we can assume that the other companies is just company Y
Keeping with the 1:4 ratio we can assume that 20 vials came from X and 80 came from Y
Then 2 ineffective vials are from X and 1.6 came from Y
Then P(an ineffective vial came from X) = 2/3.6 = 10/18 = 5/9
Then P(that this shipment came from Company X) = 30C1(5/9)1(4/9)29
Thank you.
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