At a price of x dollars, the supply function for a music player is ( = 9be "", where q is in thousands of units. How many music players will be supplied at a price of 225? (Round to the nearest thousand.) thousand units Find the marginal supply Marginal supply (X) = Which is the best interpretation of the derivative? The rate of change of the quantity supplied as the price increases The number of units that will be demanded at a given price The quantity supplied if the price increases The rate of change of the price as the quantity supplied increases The price at a given supply of units