distribution shows the joint probability
distribution of two random variables.
Suppose that the position
of the center of a hole can vary in both
the 'x' and 'y' directions and that the
distribution of the center position in both
the 'x' and 'y' directions conforms to a
The bivariate probability
distribution would be a three dimensional
surface showing the probability of the center
of a hole being in any position in the x-y
plane. This surface would allow you to solve
problems such as calculating the probability
of a hole center being one standard deviation
in 'x' and 2 standard deviations in 'y'
from the mean position.
The shape of the surface depends
on the standard
deviation in the 'x' and 'y'
directions, and whether the values of x
and y are correlated.