# QMS 202 Lecture Notes - Contingency Table, Peanut Butter, Test Statistic

## Document Summary

Outcomes: conduct a chi-square test for the difference between two proportions, conduct a chi-square test for the difference among more than two proportions, conduct a chi-square test of independence. It is denoted by the symbol: it is positively skewed. 2c: it is always non-negative value, it has only one parameter, called the degrees of freedom. The shape of a chi-square distribution curve is skewed to the right for small df and becomes symmetric for large df. (there is a family of chi-square distributions) Chi-square test: this test is available in which there is no assumption regarding the shape of the population, this test is for qualitative data. Examples include gender, province of birth, or brand of peanut butter purchased. The cells in the table indicate the frequency for each row and column combination. Items not of interest n 1 - x. 1x = number of items of interest in group 1.