A certain type of digital camera comes in either a 3-megapixel version or a 4-megapixel version. A camera store has received a shipment of 18 of these cameras, of which 7 have 3-megapixel resolution. Suppose that 5 of these cameras are randomly selected to be stored behind the counter, the other 13 are placed in a storeroom Let X = the number of 3-megapixel cameras among the 5 selected for behind the counter storage.
(a) Compute P(X = 3).
(b) Compute P(X > 3).
(c) Calculate the mean of X.
(d) Calculate the standard deviation of X.