A computer monitor manufacturer subcontracts its major parts to four vendors: A, B, C, and D. Past records show that vendors A and C provide 30% of the requirements each, vendor B provides 25%, and vendor D provides 15%. In a random sample of 10 parts, 4 were found to be nonconforming. It is known that vendors A and C operate at a level of 5% nonconformance rate, while vendors B and D are at 10% and 15%, respectively. What is the probability that the sample came from vendor A? From vendor B? From vendor C?
At next week’s church bazaar, Joseph and his cousin Jeffrey must arrange six baseballs, six footballs, six soccer balls, and six volleyballs on the four shelves in the sports booth sponsored by their Boy Scout troop. In how many ways can they do this so that there are at least two, but no more than seven, balls on each shelf? (Here all six balls for any one of the four sports are identical in appearance.)
