Mei wants to study whether heart rate increases more during certain exercises than during others. She designs an experiment to test the heart rates of classmates in the morning and in the evening for three days, immediately after doing jumping jacks, doing push-ups, or running in place. What is the dependent variable in this experiment?

The dependent variable is the result Mei measures to see how it changes with the conditions of the experiment. She measures classmates’ heart rates after different exercises and at different times, so the dependent variable is heart rate. Type of exercise and time of day are conditions being changed or compared.

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