Astore gets 50% of its items from factory 1, 30% from factory 2, and 20% from factory 3 • 2% of factory 1’s items are defective • 3% of factory 2’s items are defective • 4% of factory 3’s items are defective • if an item from the store is found to be defective, find the probability that it comes from factory • 1 = factory 1, 2 = factory 2, 3 = factory 3 • = defective