\documentclass[12pt]{article} %\usepackage{amsbsy} % for \boldsymbol and \pmb %\usepackage{graphicx} % To include pdf files! \usepackage{amsmath} \usepackage{amsbsy} \usepackage{amsfonts} %\usepackage[colorlinks=true, pdfstartview=FitV, linkcolor=blue, citecolor=blue, urlcolor=blue]{hyperref} % For links \usepackage{fullpage} % Good for US Letter paper \topmargin=-0.9in \textheight=9.5in \usepackage{fancyhdr} \renewcommand{\headrulewidth}{0pt} % Otherwise there's a rule under the header \setlength{\headheight}{15.2pt} \fancyhf{} \pagestyle{fancy} \cfoot{Page \thepage {} of 2} % %\pagestyle{empty} % No page numbers \begin{document} %\enlargethispage*{1000 pt} \begin{flushright} Name \underline{\hspace{60mm}} \\ $\,$ \\ Student Number \underline{\hspace{60mm}} \end{flushright} %\vspace{1mm} \begin{center} {\Large \textbf{STA 442/2101 F 2012 Quiz 5}}\\ %\vspace{4 mm} \end{center} \begin{enumerate} \item (5 points) For this question, you may use two facts about the multinomial without proof: \begin{itemize} \item The unrestricted MLE is the vector of sample proportions $\overline{\mathbf{Y}}$. \item The likelihood function may be written $L(\boldsymbol{\theta})=\theta_1^{n\overline{y}_1} \, \theta_2^{n\overline{y}_2} \cdots \theta_c^{n\overline{y}_c}$. \end{itemize} Denoting the \emph{restricted} MLE (restricted by $H_0$) as $\widehat{\boldsymbol{\theta}} = (\widehat{\theta}_1, \ldots \widehat{\theta}_c)$, show that the likelihood ratio test statistic \begin{displaymath} G^2 = -2 \log \left( \frac{\max_{\theta \in \Theta_0} L(\theta)} {\max_{\theta \in \Theta} L(\theta) } \right) = 2n \sum_{j=1}^c \overline{y}_j\log \left(\frac{\overline{y}_j} {\widehat{\theta}_j}\right) \end{displaymath} \newpage \item In a preference test of two (not three) detergents, eighty consumers out of 120 preferred Brand $A$ over Brand $B$. \begin{enumerate} \item (2 points) Calculate the likelihood ratio test statistic for the null hypothesis of equal preference. Show some work. The final answer is a number. \textbf{Circle the number}. \vspace{130mm} \item (3 points) The critical $\chi^2$ value at $\alpha=0.05$ is 3.841. In plain, \textbf{non-statistical language}, what do you conclude from this test? You cannot get marks for this part without a reasonable answer to (a). \end{enumerate} \end{enumerate} \end{document} \vspace{25 mm}