Pondside Apartments is a 900-unit apartment complex. When the apartments are 90% occupied, monthly operating costs total $ 226 comma 220. When occupancy dips to 80%, monthly operating costs fall to $ 220 comma 640. The owner of the apartment complex is worried because many of the apartment residents work at a nearby manufacturing plant that has just announced it will close in three months. The apartment owner fears that occupancy of her apartments will drop to 70% if residents lose their jobs and move away. Assuming the same relevant range, what can the owner expect her operating costs to be if occupancy falls to 70%?