Belinda asked her teacher, "What could make turtles go faster?" Her teacher replied, "I don't know. See if you could find out."
So Belinda did a lot of research in the library and come upon the idea that
eating carrots will make turtles go faster. She decided to test her ten turtles.
She fed five turtles their normal turtle food. She fed the other five carrots. All
the turtles got their normal sleep and water requirements. Then, after a week
she had a turtle race. She kept a record of the times and realized that she was
wrong. In fact, all the carrot-eating turtles finished last.

How was the dependent variable measured?

The amount of sleep the turtles received

How fast the turtles ate

The turtle's speed in the race

How much the turtles ate