posted by Anna on .
At a quality control checkpoint on a manufacturing assembly line, 8% of the items failed check A, 10% failed check B, and 2% failed both checks A and B.
a. If a product failed check A, what is the probability that it also failed check B? b. If a product failed check B, what is the probability that it also failed check A?
c. What is the probability that a product failed either check A or check B?
d. What is the probability that a product failed neither check A nor check B?
I am not good with probability and the percentages are really throwing me off. Any help would be great.
a)1/4 (25%) of those that failed A also failed B. That leaves you with 1/4 or 8% or 2% failing both.
b) Similarly, 1/5 (20%) of those that failed B also failed A.
c) Add the fractions that failed A only, B only, and both. I get 8% + 6% + 2% = 16%
That fraction failed A only, B only or both.