Question: Various claims are often made for surveys. Why is each of the following claims not correct?

a) It is always better to take a census than to draw a sample.

b) Stopping students on their way out of the cafeteria is a good way to sample if we want to know about the quality of the food there.

c) We drew a sample of 100 from the 3000 students in a school. To get the same level of precision for a town of 30,000 residents, we'll need a sample of 1000.

d) A poll taken at a statistics support Web site garnered 12,357 responses. The majority said they enjoy doing statistics homework. With a sample size that large, we can be pretty sure that most Statistics students feel this way, too.

e) The true percentage of all Statistics students who enjoy the homework is called a "population statistic."