2. rThis question refers to the random variables X and Y from Q1. Use your calculated values from that question while answering this question. (a) Let Z = X all", where a is a. constant to be specied. There is one value of a for which Y and Z are uncorrelated. Find this value of a. [3 marks] (b) Let H" = Y + 5X, where l) is a. constant to be specied. There is one value of i) for which X and H; are uncorrelated. Find this value of l). [3 marks]