4a. 13 out of 8,000 is about 1 in 600, so that is about the probability that the next one will be defective.
4b. 1 in 600 is a lot less than 1%, so the manufacturer did reach his goal.
By the way, ithink the one above these might be wrong. i think you have calculated the probability of the next one being chipped, rather than ofthe next one, not being chipped. So I am guessing that the answer ofr that one should be 24/25.
