+\documentclass[a4paper]{article}
+\usepackage[a4paper,margin=2cm]{geometry}
+\usepackage{amsmath}
+\usepackage{amssymb}
+\usepackage{tcolorbox}
+\usepackage{fancyhdr}
+\usepackage{pgfplots}
+\usepackage{tabularx}
+
+\pagestyle{fancy}
+\fancyhead[LO,LE]{Unit 3 Methods Statistics}
+\fancyhead[CO,CE]{Andrew Lorimer}
+
+\setlength\parindent{0pt}
+
+\begin{document}
+
+ \title{Statistics}
+ \author{}
+ \date{}
+ \maketitle
+
+ \section{Conditional probability}
+
+ \[ \Pr(A|B) = \frac{\Pr(A \cap B)}{\Pr(B)} \quad \text{where } \Pr(B) \ne 0 \]
+
+ \[ \Pr(A) = \Pr(A|B) \cdot \Pr(B) + \Pr(A|B^{\prime}) \cdot \Pr(B^{\prime}) \tag{law of total probability} \]
+
+ For independent events:
+
+ \begin{itemize}
+ \item \(\Pr(A \cap B) = \Pr(A) \cdot \Pr(B)\)
+ \item \(\Pr(A|B) = \Pr(A)\)
+ \item \(\Pr(B|A) = \Pr(B)\)
+ \end{itemize}
+
+\end{document}