D Question 1 2.5 pts In an experiment to determine how calories in beverages affect appetite, researchers randomly assigned volunteers to one of four treatments: 150 calories of apple slices, 150 calories of applesauce, 150 calories of apple juice, and 150 calories of apple juice with added fiber. Fifteen minutes later, researchers provided each participant with a large bowl of pasta and measured how many calories each person consumed. The apple slice group ate 190 fewer calories, on average, compared to the other three groups. Identify one variable that researchers kept the same in this experiment. O the amount of time that subjects were given between the treatment and the bowl of pasta O the amount of time that subjects were given to eat the apple snack O the number of calories consumed O the amount of time that the subjects were given to eat the pasta D Question 2 2.5 pts Researchers randomly assigned 408 adults with persistent asthma to take one of two treatments: an inhaled medicine with a vitamin D supplement or the inhaled medicine with a placebo. Results: After seven months, the vitamin D users were no less likely to experience reduced air flow, hospitalization, or the need for additional medicine. Identify one variable that researchers kept the same in this experiment. O the amount of time they spent exercising the need for reduced air flow, hospitalization, or the need for additional medicine O the age of the participants O the amount of time for treatment D Question 3 2.5 pts Workers who survive a layoff of other employees at their location may suffer from "survivor guilt." A study used as subjects 120 students who were offered an opportunity to earn extra course credit by doing proofreading. Each student worked in the same cubicle as another student, who was an accomplice of the experimenters. At a break midway through the work, one of three things happened Treatment 1: The accomplice was told to leave; it was explained that this was because he or she performed poorly. Treatment 2: It was explained that unforeseen circumstances meant there was only enough work for one person. By "chance," the accomplice was chosen to be laid off. Treatment 3: Both students continued to work after the break. The students' work performance after the break was compared with performance before the break. What is the purpose of random assignment in the experiment described? O The purpose of random assignment is to provide a baseline for comparing the effects of other treatments. O The purpose of random assignment is to avoid confounding by creating three groups of students that are roughly equivalent at the beginning of the experiment. O The purpose of random assignment is to be able to m eneral claim about all students who were offered an opportunity to earn extra course credit O The purpose of random assignment is so neither the subjects nor those who interact with them and measure the response variable know which treatment a subject is receiving