The weekly demand function for video game consoles is given by p = d(x) = 600 - 12x2 where a is the number of thousands of consoles and p is in dollars. Find the average rate of change of the unit price as the quantity demanded goes from 3000 consoles to 6000 consoles. -108 dollars per thousand consoles -88 dollars per thousand consoles -93 dollars per thousand consoles -113 dollars per thousand consoles -123 dollars per thousand consoles