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Basic Question 2 of 3
In a certain electric motor factory, production lines 1, 2, and 3 produce 10%, 40%, and 50%, respectively, of the total output. Of their respective outputs, 5%, 3%, and 1% are defective. What is the probability that a defective motor came from production line 2?
B. 0.0340
C. 0.5455
A. 0.0220
B. 0.0340
C. 0.5455
User Contributed Comments 9
| User | Comment |
|---|---|
| azramirza | Or .05*.10=0.0050 .03*0.40=0.0120 .01*.50=0.0150 total=0.0220 Machine2to be defective=0.0120/0.220=0.0545 |
| EminYus | How come there is no multiplication of the event in the above example? I got the answer, but don't understand how it relates to Bayes. P(E | I) = P(I |E) / P(I) x P(E) |
| EminYus | nevermind, broke it all down and figured it out |
| harpalani | Forget what Bayes said. Let's look at it this way: Prd Line % Prod. % default Prob. of default 1 10% 5% 0.005 2 40% 3% 0.012 3 50% 1% 0.005 Prob. tht defective production came from prod line 2 = 0.012/(0.005+0.012+0.005) = 54.45% |
| NikolaZ | Bayes formula took forever, I assumed 100 motors, out of 100: 2.2 were defective, out of these 2.2, 1.2 of the defects belonged to Production(2) Therefore: 1.2/2.2 = 0.5455 |
| bidisha | How can i change the settings in my ba2 plus professional so that it will go up to 3 decimal places rather than rounding everything down auto to 2 decimal?? |
| Seancfa1 | Read the manual! 2nd format choose amount of d.p enter 2nd quit |
| thebkr7 | @Harpalani. Perfectly explained Thanks |
| cfastudypl | Well done Harpalani, I agree with you, because following the basic way of computing for probability will yield the same result. |
You have a wonderful website and definitely should take some credit for your members' outstanding grades.
Colin Sampaleanu
Learning Outcome Statements
calculate and interpret an updated probability in an investment setting using Bayes' formula
CFA® 2024 Level I Curriculum, Volume 1, Module 4.