Identify whether the following scenario is experimental or an observational study: A group of students are interested in knowing if the number of times they can sink a basketball is related to the color of the basketball. The students shoot a series of baskets and record their success using a regulation colored basketball. They then switch to a blue colored basketball and shoot a same series of baskets.

Identify whether the following scenario is experimental or an observational study: A group of students want to know is there is any association between attending an SAT Prep class and scores achieved on their SAT exam. The students use a survey to collect their data from both students who took an SAT Prep class and those that did not take an SAT Prep class.

Identify whether the following scenario is experimental or an observational study: A statistics professor announces a study session to be held the night before the test. The professor then lists the students who attended the session and compares their scores to the remaining students scores.

What experimental design is this: Volunteers suffering from insomnia were divided into two groups. The first group was assigned a special no-dessert diet while the other group continued desserts as usual. Half of the people in these groups randomly assigned to an exercise program, while others did not exercise. After the experiment, those who ate no dessert and engaged in exercise showed the most improvement

Group the runners into pairs based on their age and gender, and then randomly assign treatments within each pair, the type of design used here is