A psychologist needs 10 pigs for a study of the intelligence of pigs. She goes to a pig farm where there are 40 young pigs in a large pen. Assume that these pigs are representative of the population of all pigs. She selects the first 10 pigs she can catch and uses them for her study.
a. Do these 10 pigs make a random sample?
b. Are these 10 pigs likely to be representative of the entire population? Why or why not?
c. If these 10 pigs do not form a random sample, what type of sample is it?
d. Can you suggest a better procedure for selecting a sample of 10 from the 40 pigs in the pen?