Suppose a Ries Engineering conducted 8-week training to its workers to improve their productivity. The company wants to test whether the training increased the productivity of its workers. What is the problem in using two independent sample t-test for this research problem? What type of t-test would be appropriate? What are the assumptions? Suppose the you are given measured productivity before and after the training, what would be the next step to conduct the research How would you formulate the hypothesis using Di component?