help starting a triple integral/center of mass problem

i need help setting up the integral expressions to compute the centroid please!

the solid bounded by the paraboloids z=1+x^2+y^2 and z=5-x^2-y^2 with density proportional to the distance from the plane z=5

so i need to find the boundaries for x,y, and z, which i think i can do if i set x=0 then y=0?

my main problem is figuring out how to put the density into an equation. i think it has to do with the distance formula. f(x,y,z)= k* sqrt of 5? any hints would help a ton! thanks!