a fast-food restaurant has 5 items on special, here are the prices(including tax): soda= 1, fries = 1, pizza slice = 2, chicken sandwich =3, burger deluxe = 4. you wish to buy a soda and 2 additional food items at random from among the 4 food( choices given). it is possible to buy the same food twice. let X = the total cost of the 3 items you purchase. evaluate the probability function p(x) at all possible values for X.