STATS 250 Lecture Notes - Lecture 15: Count Data, Test Statistic, Standard Deviation

• School: U of M
• Department: Statistics
• Course: STATS 250
• Professor: Brenda Gunderson

Document Summary

Stats 250: introduction to statistics - lecture 15: chi-square analysis. Used to assess if a particular discrete model is a good fitting model for a discrete characteristic, based on a random sample from the population. Used if two or more populations are homogenous (alike) with respect to the distribution of some discrete (categorical) variable. Is the distribution of opinion on legal gambling the same for adult. Used to assess if two discrete (categorical) variables are independent for a population, of it there is an association between two variables. Is there an association between satisfaction with the quality of public schools (not satisfied, somewhat satisfied, very satisfied) and political party (republican, democrat, etc. All three tests are based on an x2 test statistic that, if the corresponding h0 is true and the assumptions hold, follows a chi-square distribution with some degrees of freedom, written x2(df) If we have a chi-square distribution with df = degrees of freedom, then .