please answer 3,4

improvement 3. A research organization designed an experiment to test the effects of an educational TV show and its website on the learning of mathematical reasoning among upper elementary school students. The website had two type of activities: basic and advanced. The available students were randomly assigned to watch the show or not. Among these same students, some were randomly assigned to skip the website while others were randomly assigned to use the website. Among the latter. some were randomly assigned to do only the basic activities and the rest to do both the basic and advanced activities. Then, students took a variety of mathematical reasoning tests, 4. In a Time Magazine Article "Please, Please, Go to Sleep" it was noted that about 60% of a child's growth hormone is secreted during sleep, so it is believed that a lack of sleep in children might stunt growth. a. What is the response variable and what is the explanatory variable in this association? b. Explain why it is difficult (and unethical) to get objective verification of this possible causal relationship c. How would this work as an observational study? Describe how the study would be implemented. Would we still be able to conclude a causal relationship? What would be able to conclude from an observational study