an air conditioning manufacturer produces room air conditioner at plants in houston, phoenix, and memphis. there are sent to regional distributors in...

an air conditioning manufacturer produces room air conditioner at plants in houston, phoenix, and memphis. there are sent to regional distributors in dallas, atlanta, and denver. the shipping cost vary, and the company would like to find the least cost-way to meet demands at each of the distribution centers. Dallas needs to receive 800 per month, atlanta needs 600, and denver needs 200.