Find the average rate of change for the given function from x = −1 to x = 2. four thirds negative four thirds negative three fourths three fourths i think that x is positive three, but i can't figure out y. a negative 4 maybe? !

You work for a landscape company that just got a contract to re-mulch a park. the area that needs mulching is 30 feet by 60 feet. they want a 3 inch layer of much on the area. the company has bags of mulch that cover 2 cubic yards that cost $4.00 per bag. how much will it cost the consumer just in materials to re-mulch the area (round to the nearest dollar)?