JointProbability.md (659B)
1 # Joint Probability 2 3 Stats L2 + L6 4 5 **Definition:** A joint probability is the probability of multiple conditions. 6 7 An example of this is that 48% of voters are in favor of the bill and democrats. This is the joint probability of any given voter being both a democrat and in favor of the bill. 8 9 ## Joint PMF (L6) 10 11 The joint PMF is simply the PMF that represents the probability of joint outcomes. 12 13 The joint PMF function, much like normal PMF functions, can be stated as P_{X,Y}(x,y) where X and Y are the joint conditional probabilities and x,y are the joint conditions we are evalulating for. 14 15 An important note is that the sum of all x,y for P{X,Y} = 1.