So 0 be the cumulative probability distribution function (CDF) for the random variable X. COF given a) Give the probability distribution function (PDF) for the random variable X. Please use a lower case a in your expressions. f (20 ) = ;* ? f ( 20 ) = ;x ( ? b) If X describes the size (square footage) of a building before needing to include a toilet. How many toilets, on average, do you expect to be in buildings with 2485 square feet? ( use at least four digits after the decimal if rounding...) c) Plot the pdf of X then select the graph below that looks closest to correct