You wonder how many cars there are in your area. you call up the ford dealership and ask how many fords they’ve sold. they report that they’ve sold a total of 15,000 cars. you then take a lawn chair and camp out on a busy road and count cars. you count 1200 cars and note that 700 of them are fords. estimate the number of cars in your area.

Over the course of the school year, you keep track of how much snow falls on a given day and whether it was a snow day. your data indicates that of twenty-one days with less than three inches of snow, five were snow days, while of the eight days with more than three inches of snow, six were snow days. if all you know about a day is that it is snowing, what is the probability that it will be a snow day?