Because the disease affects a shark’s ability to extract oxygen from the water, the zoologist also measures the shark’s blood oxygen content. Th e zoologist finds that, on average, shark’s blood oxygen content is 4.2%.
a. Identify the variable measured on each shark.
b. Is the variable categorical or quantitative?
c. Identify at least two statistics that the zoologist could use to summarize the variable.
d. Identify at least one graph that the zoologist could use to summarize the variable.

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.