SOLUTION: Four terms are taken at random from a box of 12 items and inspected . The box is rejected if more than 1 item is found to be faulty. If there are 3 faulty items in the box, find th

Algebra ->  Probability-and-statistics -> SOLUTION: Four terms are taken at random from a box of 12 items and inspected . The box is rejected if more than 1 item is found to be faulty. If there are 3 faulty items in the box, find th      Log On


   



Question 927187: Four terms are taken at random from a box of 12 items and inspected . The box is rejected if more than 1 item is found to be faulty. If there are 3 faulty items in the box, find the probability that the box is accepted
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
12 items: 3def, 9good
p(def) = 1/4, p(good) = 3/4
4 drawn from box
P(box accepted) = P(x ≤ 1def)= P(0) + P(1) = (3/4)^4 + 4(3/4)^3(1/4)
Using a TI calculator 0r similarly a Casio fx-115 ES plus
P(x ≤ 1)= binomcdf(12, .25, 1) = .1584 0r 15.84%