The required cooling capacity, in BTUs, for a room air conditioner is directly proportional to the area of the room being cooled. A room of $280$ square feet requires an air conditioner whose cooling capacity is $4760$ BTUs.

(a) What is the constant of proportionality, and what are its units? Choose BTUs feet square feet BTUs per foot BTUs per square foot help (numbers)

(b) If an air conditioner has a cooling capacity of $6630$ BTUs, how large a room can it cool? Choose BTUs feet square feet BTUs per foot BTUs per square foot help (numbers)