A high school track coach is interested in finding out if carbohydrate consumption helps increase running times in her athletes. She asks half of her team to eat a huge pasta dinner the night before a big meet and asks the other half of her team to eat a large steak and no carbohydrates.

Write a hypothesis in an if-then statement.
Identify the independent variable (IV).
Identify the dependent variable (DV).
Identify the experimental group.
Identify the control group.
What is the purpose of using random assignment?

"If athletes consume carbohydrates, their running times will increase"

Independent variable: whether the athletes eat carbohydrates

Dependent variable: running times

Experimental group: the group that eats the pasta dinner

Control group: the group that eats the steak dinner with no carbohydrates

The purpose of using random assignment is to make sure that there are no selection factors that might affect the group. For example, if she asked the boys to eat one food and the girls to eat another, that wouldn't be random, and would introduce the sex of the athletes as a possible confounding variable.

Explanation:

(note that this is kind of a weird question: why would you want to *increase* running times?)