Dr. Martinez is studying the effects of diet on the time it takes subjects to solve geometry problems. Each morning for two weeks, subjects in Dr. Martinez's study eat a breakfast that is either high in carbohydrates or high in protein. Dr. Martinez then measures the subjects' time it takes to solve geometry problems. What is the dependent variable in this study?

The answer is the time it takes subjects to solve the problems.

Explanation:

In experimental research, the dependent variable is a factor expected to change by the effects of an independent variable. An easy way to tell one from the other is to remember: Independent causes change in dependent. For this reason, the dependent variable may also be called "outcome" variable" or "predicted variable".

In the example, the time it takes to solve the problems depends on the diet plan.