Consider the data given in Example 4. The marginal PDF of X is obtained as follows:
APPENDIX A: A REVIEW OF SOME STATISTICAL CONCEPTS 875
EXAMPLE 5 (Continued) Likewise, the marginal PDF of Y is obtained as f (y = 3) = J2 f (x, y) = 0.27 + 0.08 + 0.16 + 0 = 0.51
x f (y = 6) = J2 f (x, y) = 0 + 0.04 + 0.10 + 0.35 = 0.49
As this example shows, to obtain the marginal PDF of X we add the column numbers, and to obtain the marginal PDF of Ywe add the row numbers. Notice that J2x f(x) over all values of Xis 1, as is J2y f (y) over all values of Y(why?).
Conditional PDF. As noted in Chapter 2, in regression analysis we are often interested in studying the behavior of one variable conditional upon the values of another variable(s). This can be done by considering the conditional PDF. The function
Was this article helpful?
Learning About The Rules Of The Rich And Wealthy Can Have Amazing Benefits For Your Life And Success. Discover the hidden rules and beat the rich at their own game. The general population has a love / hate kinship with riches. They resent those who have it, but spend their total lives attempting to get it for themselves. The reason an immense majority of individuals never accumulate a substantial savings is because they don't comprehend the nature of money or how it works.