a) It is pretty much about how to prove the answer. We are able to figure out easily that what the answer is if you sit on the desk and think for just 5 minutes. The answer is a/2, but why? how? Please use the PDF method and |x-a| to demonstrate the answer.
b) It is a little bit twisted problem because now we need to deal with the exponential RV in this question. Fortunately, you are not going to be worried to solve this problem if you know the PDF. when the lamda is S, Just integrate s*(e^(-sx))*|x-a| and get the value. That would be the answer of this particular question.
Good luck everybody.
P.S
If you believe my explanation is totally out of the line, Please let me know, or reply on this page.
