What is the annual cost of the existing system for 12,500 square feet at $3.75 per square foot?

To calculate the annual cost of the existing system for a space measuring 12,500 square feet at a rate of $3.75 per square foot, you multiply the total square footage by the cost per square foot.

So, the calculation would be:

12,500 square feet * $3.75/square foot = $46,875.

This result reflects the total annual expense for maintaining or operating the existing system within that square footage. The correct understanding of the multiplication, along with attention to the units being used—square feet and cost per square foot—leads to the proper answer, which confirms that the annual cost is indeed $46,875.