Everything about one variable \( \mathbb{E}(X),\; \) \( Var(X),\;\) \( \gamma(X),\; \) \( 0.75 \; percentile,\; \) etc.
Double Entry Tables \( \mathbb{E}(X|Y),\; \) \( Var_{between}(X),\;\) \( Var(Y|X) \) etc.
Chi-Squared, Cramér's V \( \chi^2, \; \chi^2_N, V \)
Relations between variables \( \rho^2,\; \) \( \eta^2_{Y|X},\;\) \( \eta^2_{X|Y},\;\) \( \chi^2 \) etc.
Bayes' theorem \( P(A \cup B ) \) \( = P(A|B)P(B) \)
With replacement \( P( X = x ) \) \( = \binom{n}{x}p^x(1-p)^{n-x} \)
Index numbers \( NIBM \) = \( \dfrac{ x_{t} }{ x_{t-1} } \)