Question 1192369
as far as i know, the sum of all probabilities must be equal to 1.
since there are only 3 possibilities, then the sum of those 3 probabilities must be equal to 1.
p(a) = .990
p(b) = .001
(a) p(c) must be equal to 1 - .990 - .001 = 1 - .991 = .009.
(b) the probability that the machine does not underfill is equal to 1 minus the probability that the machine does underfill = 1 minus p(b) = 1 minus .001 = .999, which is also equal to .990 (specs) plus .009 (overfill).
(c) the probability that the machine either overfills or underfills is equal to 1 minus the probability that the machine fills to specifications = 1 minus .990 = .010, which is also equal to .001 (underfill) plus .009 (overfill).
that's what i get.