Question

A scientist is hoping to compare the mean levels of DDT toxin found in three species of fish in a local river. He randomly samples 50 of each species to use in the analysis. For each fish, he measures the amount of DDT toxin present. Ideally he will be able to rank the species based on the mean level of toxin found in each of the three species. Identify the response variable in this study. The number of fish The three fish species The amount of DDT in a fish The scientist

Answer 1

The amount of DDT in a fish

Explanation:

The response variable is the focus of a question in a study or experiment. Is the variable you are measuring and trying to explain.

In this case, is what the scientist is measuring and using to compare the fish species: the amount of DDT in a fish.

The explanatory variable is what drives changes in the response variable (usually the indendent variable). In this study, the explanatory variable would be the species of fish.