Answer the following questions: 0.0 00 f(x) 0.6 0.8 1.0 0.2 0.4 5 10 15 20 25 30 X a. The graph above shows three gamma densities F(3,1), F(10,1) and F(1,1); Please identify which one is which. (Place your labels on the plots) b. Refer to question (a). Find the mean and the variance and the MGF of the three Gamma densities. c. Suppose that X follows the uniform distribution on (0, n). Find the mean and variance of X.