An automobile repair shop makes an initial estimate X in hundreds of dollars of the amount of money needed to fix a car after an accident. Suppose that X has the uniform distribution over [5,9]. Given that X = r, the final payment Y has the uniform distribution over (r, r + 2). What is the (marginal) expectation of Y? (There are three ways to solve this problem: 1. It is okay to give an argument based on intuition; 2. It is possible to do direct computation; 3. Use the next problem.)