A machine to detect improper welds in a fabricating shop detects 80 percent of all improper welds

Microsoft Word – homework_2_2005.docProblem 1

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.

1. (a)  What is the probability that a weld that the machine indicates to be defective is in fact satisfactory?
2. (b)  What is the probability that a weld that the machine indicates to be satisfactory is in fact defective?
3. (c)  Compare the probabilities in (a) and (b) and comment on their relative magnitudes. expert assignment assistance.