1.1 g/cm^3 vs 0.9 g/cm^3, im sure there are more precise values out there but that's all I can remember off the top of my head...and it would make sense if you think about people in a swimming pool, water is 1.0 g/cm^3
You can calculate it from there, I remember calculating a cube of 7.2 cm dimensions for fat...muscle is for sure smaller...too lazy to do it now though, but its not too difficult a calculation (I'm quite the geek btw but it's nice to quantify stuff)