Consider how the sample for the study was selected. If the study was conducted by taking a random sample, explain (in enough detail that someone could follow your directions to obtain the sample) how it could have been done. If the study was not conducted by taking a random sample, explain how you could modify the study design to make it be a random sample, and explain (in enough detail that someone could follow your directions to obtain the sample) how it could have been done.

A zoologist at a large metropolitan zoo is concerned about a potential new disease present among the 243 sharks living in the large aquarium at the zoo. The zoologist takes a random sample of 15 sharks from the aquarium, temporarily removes the sharks from the tank, and tests them for the disease. He finds that 3 of the sharks have the disease.