A circular swimming pool holds 1.22 x 10^6 cubic inches of water. It is being filled at a rate of 1.5 x 10^3 cubic inches per minute. How many hours will it take to fill the swimming pool?

You can set up a proportion:

1.5*10^3/1=1.22*10^6/x

Cross multiply:

1.22*10^6=1.5*10^3x

Solve for x:

x = (1.22*10^6) / (1.5*10^3)

x≈813.33

Now, Divide 813.33 by 60 because the question asks for hours, not minutes:

813.33/60≈13.56

So it will take approximately 13.56 hours for them to finish filling up the swimming pool.