Question

2. A population of 600 semiconductor wafers contain wafers from three lots. The whether they conform to a thickness specification. The following table presents the number of wafers in each category. A wafer is chosen at random from the population Lot Conforming 88 nonconforming 12 165 260 If the wafer is conforming, what is the probability that it is from Lot A? If the wafer is not from Lot C, what is the probability that it is conforming?

Answer 1

conforming non-conforming Total 12 100 165 35 200 300 260 40 513 GOO 89 a) PCA If water conforming) : water conforming = 513 event A = 88 PCA if water conforming ) = 80 = 0.1715 b) PC conforming if not from e) wafer not from c = 600-300 - 300 event conforming = 88+165 - 253 :p (conforming if not from C) = 253 300 =0.8433 ans & a= 0.1715 b=0.8433