STAT 11300 Study Guide - Final Guide: Chi-Squared Distribution, Null Hypothesis, Sampling Distribution
Document Summary
Chi-square statistic- denoted as x2 is a measure of how far the observed counts in a two-way table are from the expected counts. The formula for the statistic is: x2= e(sigma) (observed count-expected count) The sampling distribution of the chi-square statistic x2 when the null hypothesis of no association is true is called a chi-square distribution. The chi-square distributions are a family of distributions that take only nonnegative values and are skewed to the right. A specific chi-square distribution is specified by giving its degrees of freedom. The chi-square test for a two-way table with r rows and c columns uses critical values from the chi- square distribution with (r-1) (c-1) degrees of freedom. 529 (we will only use . 05 column) no exercise 1-2 per week 3-4 per week 5+ per week. Poor health 100 120 30 20: suppose the calculated chi-square statistic was 30.
