A machine to detect improper welds in a fabricating shop detects 80 percent of all improper
welds, but it also incorrectly indicates an improper weld on 5 percent of all satisfactory welds.
Past experience indicates that 10 percent of all welds are improper.
i. What is the probability that a weld that the machine indicates to be defective is in fact
ii. What is the probability that a weld which the machine indicates to be satisfactory is in fact
iii. Compare the probabilities in (a) and (b) and comment on their relative magnitudes.