QUESTION 32 . 1 POINT To study whether there is a correlation between regular exercise and sleep, a researcher randomly selected 100 people who exercise regularly and 100 people who do not exercise regularly, and compared how many hours they sleep at night, on average. Is the study observational or experimental? If it is an experiment, what is the controlled factor? Select the correct answer below: The study is an experiment. The controlled factor is the amount of sleep. The study is an experiment. The controlled factor is the amount of exercise. The study is an observational study. The study is an experiment. The controlled factor is the survey. FEEDBACK