Please help to solve these two questions.

Detailed steps/explanation are required. Thanks!

1. Describe how one can design a hypothetical randomized control experiment to study the effect of having immigrant classmates on the test scores of native students. Suggest some impediments to implementing this experiment in practice. A group of researchers compared the average heights of children who had been beaten (i.e. spanked) by their parents and those who have never been beaten. They found that children who had been beaten were, on average, 4cm shorter than children who had never been beaten. Based on this, they concluded that beating stunts the physical growth of children. Do you agree with their inference? Why or why not