The Chi-Square Distribution: Practice 2 1.9 2008/06/22 20:42:03 GMT-5 2008/10/27 21:07:36.182 GMT-5 Susan Dean deansusan@deanza.edu Barbara Illowsky illowskybarbara@deanza.edu Susan Dean deansusan@deanza.edu Barbara Illowsky illowskybarbara@deanza.edu Connexions cnx@cnx.org elementary statistics This module provides a practice on Chi-Square Distribution as a part of Collaborative Statistics collection (col10522) by Barbara Illowsky and Susan Dean.

Student Learning Outcomes The student will explore the properties of contingency tables.

Conduct a hypothesis test to determine if smoking level and ethnicity are independent.

Collect the Data Copy the data provided in Probability Topics Practice 2: Calculating Probabilities into the table below.Smoking Levels by Ethnicity (Observed) Smoking Level Per Day African American Native Hawaiian Latino Japanese Americans White TOTALS 1-10 11-20 21-30 31+ TOTALS

Hypothesis State the hypotheses. Ho: size 12{H rSub { size 8{O} } :} {} Ha: size 12{H rSub { size 8{a} } :} {}

Expected Values Enter expected values in the above below. Round to two decimal places.

Analyze the Data Calculate the following values: Degrees of freedom = 12 Chi2 size 12{ ital "Chi" rSup { size 8{2} } } {} test statistic = 10301.8 p-value = 0 Is this a right-tailed, left-tailed, or two-tailed test? Explain why. right

Graph the Data Graph the situation. Label and scale the horizontal axis. Mark the mean and test statistic. Shade in the region corresponding to the p-value.

Conclusions State the decision and conclusion (in a complete sentence) for the following preconceived levels of α size 12{α} {} . α = 0 . 05 size 12{α=0 "." "05"} {} a Decision: b Reason for the decision: c Conclusion (write out in a complete sentence): aReject the null hypothesis α=0.01 a Decision: b Reason for the decision: c Conclusion (write out in a complete sentence):