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Engineering Data Analysis2D

Joint Probability Distributions - Theory & Concepts

Joint probability mass/density functions, marginal and conditional distributions, covariance, and correlation.

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Engineering Data Analysis

Discrete Joint Probability Explorer

Probability Distribution Table

XYX \setminus YY=1Y = 1Y=2Y = 2Y=3Y = 3g(x)g(x)
X=10X = 100.150
X=20X = 200.600
X=30X = 300.250
h(y)h(y)0.2000.5000.3001.000
Mean μX\mu_X21.00
Mean μY\mu_Y2.10
Covariance Cov(X,Y)\text{Cov}(X,Y)
2.9000

If Cov(X,Y)>0\text{Cov}(X,Y) > 0, X and Y tend to increase together. If Cov(X,Y)<0\text{Cov}(X,Y) < 0, they vary inversely. If 00, there is no linear relationship.

Probability Distribution Visualizer

Y=1Y=1
Y=2Y=2
Y=3Y=3
g(x)g(x)
X=10X=10
0.10
0.05
X=20X=20
0.10
0.40
0.10
X=30X=30
0.05
0.20
h(y)h(y)

Bubble size & opacity indicate the magnitude of the joint probability f(x,y)f(x,y).

Green bars represent the marginal distributions g(x)g(x) and h(y)h(y).