Question

Washer City: We Sell Washers… And That’s All! Washers (that is, a disc with a hole in the middle) are important in the construction of a particular subassembly, and the inside diameter of the washer has to fit a very precise specification. Based on prior (perfect) manual inspection data, 75% of washers meet specifications, 15% are too big, and 10% are too small. A new electronic inspection machine has been purchased to reduce the need for manual inspection. The electronic inspection machine correctly identifies washers that meet specifications 95% of the time, and it correctly identifies washers that do not meet specifications 80% of the time.

a. Given that a washer fails to meet specifications, what is the probability that it is too big?

b. If the electronic inspection machine reports that a washer does not meet specifications, what’s the probability that the washer actually does meet specs?

Answer 1