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A certain product must be subjected to (and pass) a sequence of various combinations of 5 tests (Tests A through E) before it may receive one of two certifications (Certification 1 or Certification 2). The diagram shows how products proceed through these tests, along with the probability of proceeding from each test to the next test or certification. For instance, the diagram shows that an item subjected to Test A has a 0.20 probability of passing Test A and being subjected to Test B next, a 0.75 probability of passing Test A and being subjected to Test C next, and a 0.05 probability of failing Test A. The probability that an item receives either of the two certifications is exactly 0.93.
Based on the information provided, select from each drop-down menu the option that creates the most accurate statement.
To the nearest hundredth, the probability that a randomly selected product subjected to Test A will receive Certification 1 is [dropdown1]
To the nearest hundredth, the probability that a randomly selected product subjected to Test A will receive Certification 2 is [dropdown2]
options : 0.86 , 0.91
Correct Answer:
Dropdown 1: 0.02
Dropdown 2: 0.91
I am sure the value 0.93 in the question is given for a reason. If you add P(1) and P(2), the answer should be 0.93.
Thus, the values in first dropdown and second dropdown should add to 0.93...Pretty straightforward.However, even if you calculate values for individual certificate, you will get the answer. But they wouldn't give probability of either be 0.93 in that case.
Solution in case we didn't know the dropdowns as in here.Certificate 2 can be received through three routes, and tests C and E move towards only 2 and have probability of passing as 1.
a) The moment test C is given, it is 100% to result in certificate 2 ( as C and E have a 100% probability of pbeing passed)
Probabilty of moving from A to C is 0.75
b) Next, if we move from A to B, the probability is 0.2, and moving to C is 0.70. Thus probabilty of reaching C via B is 0.2*0.70 or 0.14
We know beyond C, probabilty is 100%.
C) Finally, if we move from A to B , the probability is 0.2, then B to D is again 0.2 and moving to E is 0.50. Thus probabilty of reaching E via B and D is 0.2*0.2*0.5 or 0.02
We know beyond E, probabilty is 100%.
Total P = 0.75+0.14+0.02 = 0.91In the actuals, you will not have to solve this long, and two ways to answer
(1) Add the two dropdowns to get 0.93
(2) Find P of 1, which is 0.2*0.2*0.5 or 0.02, and for dropdown 2, just subtract this from 0.93 or 0.93-0.02, that is 0.91
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