what is the difference between contingency table and joint probability distribution?
Can’t believe that the distribution of the proportion is not in CFA level 1 or 2.
Contingency table is a method presenting the joint probability of two (or more, if you can make more-than-two dimensions table) variables X and Y. Each cell of the table contains the probability F(X=a, y=b) with a and b is one of possible couple of value of (X,Y). Contingency table is usually used when X and Y are two discrete variables (even thought it is also possible to use contingency table for continuous variables).
Joint probability distribution is another method presenting the joint probability of two variable X and Y. Joint probability distribution is usefull when X and Y are continuous and/or discrete variables.