\chapter{Tests Reminders} \section{$\chi^2$ test of independence} \section{$\chi^2$ test of goodness of fit} Check if the observations is in adequation with a particular distribution. \begin{example}[Mendel experiments] Let $AB$, $Ab$, $aB$, $ab$ be the four possible genotypes of peas: colors and grain shape. \begin{tabular} \toprule AB & Ab & aB & ab \\ \midrule 315 & 108 & 101 & 32 \\ \bottomrule \end{tabular} \end{example} The test statistics is: \[ D_{k,n} = \sum_{i=1}^{k} \frac{(N_i - np_i)^2}{np_i} \underoverset{H_0}{\mathcal{L}} \chi^2_{(n-1)(q-1)??} \]