A1 Computer has 15 tablets stocked, but four of them were actually defectives. A client bought two tablets from A1 Computer. If both of them are good, things are fine. If the client gets one defective machine, A1 Computer will replace it and give a $100 rebate to the client. If the clients gets two defective machines, A1 Computer will replace both of them and give a $1000 rebate to the client. What is the expected value and the standard deviation of the company's rebate? P(R) = 4/15 x 100 = 26.6% Since there were 4 defective machines then 2 x 1000 = 2000 was given away to client(s) so value = 2000 how would I find the standard deviation? I know the usual formula but where would i plug into it?