A researcher wants to examine the effects of exercise type and weight loss among college students. He randomly assigns 90 people to three different exercise regiments: pure cardio, pure weight training, and a combination of the two. He then measures each subject weight once a week during an 8-week interval. 1. What is the independent variable in this study? 2. What is the dependent variable in this study? 3. Approximately how many people should be in each group? 4. Describe one potential source of sample bias. 5 . Who is the population for this study? 6. What are the null and alternative hypotheses