STAT 301 Study Guide - Midterm Guide: Statistical Unit
Document Summary
X2 = k (observed counti expected counti)2 i=1 expected count i. X2 has an approximately chi-squared distribution with df = k 1 (for k categories), assuming a large sample size (expected counts 5 in each category) Notation: x2 ~ 2 (k 1) k - 1. Has a shape determined by the degrees of freedom. It approaches a normal distribution as the degrees of freedom increase. Reject h0 if p-value < (always true) Ex: k = 15 x2 = 24 df = 15 1 = 14 p-value = p( 14. 2 24) < . 05 p-value (. 045, . 05) For each subject (experimental unit), two different categorical variables are collected.
