A wildlife biologist examines frogs for a genetic trait that is linked to sensitivity to an industrial toxin in the environment. Suppose exposure to the toxin tends to increase the prevalence of the genetic trait in the population of frogs. Previous research has established that this trait is usually found in about 1/5 of all frogs in a ‘clean’ environment. Suppose a location is suspected of contamination. A sample of 10 frogs are collected, then examined for the genetic trait. We are asked to interpret the data collected and determine whether there is evidence suggesting contamination.

a. What values of X would you expect to see for a clean environment?

b. What values of X would indicate no evidence of toxin in the environment?

c. What values of X would suggest to you that the toxin is present in the environment?