Chemistry: homework help.... Here's the question...?

My dog weighs 58.0 lbs. I put him into a bathtub containing 47.0 gallons of water when filled to the very top. After I put him in, I collected all the water that ran over the side of the tub, and found it to be equal to 1.923 gallons. (A) What is the density of my dog in grams per cubic centimeter? (B) What if next time I do this he gains 4.0 lbs. and grows big enough to displace 2.10 gallons. Will he still have the same density? Explain and prove your answer. All work must be shown , labeled , and explained in detail. Note that where applicable, superscripts (X 2 ) can be written as X^2 and subscripts (X 2 ) can be written as X_2 if it saves you time.