Yes, yes, we know all of that. It certainly took you long enough to
get around to asking your question.
If
a = (14, 10.5, 0)
and
b = (4.62, 9.45, 0) ,
then, to begin with, neither vector has a z-component, and they
both lie in the x-y plane.
Their dot-product a · b = (14 x 4.62) + (10.5 x 9.45) =
(64.68) + (99.225) = 163.905 (scalar)
I feel I earned your generous 5 points just reading your treatise and
finding your question (in the last line). I shall cherish every one of them.
Density= how much mass is in a certain volume
Therefore, you do (mass/volume).
density of the block is
36g/9cm3
or
4g/cm3
Meaning that there is 4 grams of mass in each cm3.