Joint probability distribution - Wikipedia
en.wikipedia.org › wiki › Joint_probability_distributionIf the points in the joint probability distribution of X and Y that receive positive probability tend to fall along a line of positive (or negative) slope, ρ XY is near +1 (or −1). If ρ XY equals +1 or −1, it can be shown that the points in the joint probability distribution that receive positive probability fall exactly along a straight line. Two random variables with nonzero correlation are said to be correlated.
Joint probability distribution - Wikipedia
https://en.wikipedia.org/wiki/Joint_probability_distributionGiven random variables , that are defined on the same probability space, the joint probability distribution for is a probability distribution that gives the probability that each of falls in any particular range or discrete set of values specified for that variable. In the case of only two random variables, this is called a bivariate distribution, but the concept generalizes to any number of random variables, giv…
Joint Distributions, Continuous Case
faculty.math.illinois.edu › ~hildebr › 408• Relation to variance: Var(X) = Cov(X,X) • Variance of a sum: Var(X +Y) = Var(X)+Var(Y)+2Cov(X,Y) 5. Independence of random variables: Same as in the discrete case: • Definition: X and Y are called independent if the joint p.d.f. is the product of the individual p.d.f.’s: i.e., if f(x,y) = f X(x)f Y (y) for all x, y. 1