In: Statistics and Probability
There are 3 car mechanics. They all fix a number of cars each year. Each mechanic (Mike, John, and Nick) have an rate for failing car parts. Find the probability that a car part fails. Hint. rate # of failed cars/ car work per person i.e. 2/40 for Mike.
Mechanic | Portion of Car Work | # of failed cars |
---|---|---|
Mike | 40 | 2 |
John | 10 | 3 |
Nick | 50 | 4 |
Also, if the car part fails, find the probability that the car was produced by
A. Mike
B. John
C. Nick
a)
P(car part fails) = P(part fails|it is fixed by mike) +P(part fails|it is fixed by john) + P(part fails|it is fixed by nick)
= 2/40 + 3/10 + 4/50
= 43/100
= 0.43
b)
i)
P(it is fixed by mike | car part fails) = (2/40)/0.43
= 5/43
ii)
P(it is fixed by john | car part fails) = (3/10)/0.43
= 30/43
iii)
P(it is fixed by nick | car part fails) = (4/50)/0.43
= 8/43