The purpose of this activity is to gain experience conducting a chi-square test of independence using technology.

Recall the report On the Front Line: The Work of First Responders in a Post-9/11 World. We will use data from this report to investigate the question: Are alcohol-related problems among New York firefighters associated with participation in the 9/11 rescue?

Here again are our observed data:

Participated in 911 rescue with no risk for alcohol problems is 793

Did Not Participate in 911 rescue is 441 (793+441) = 1234

Participated in 911 rescue with moderate to severe risk for alcohol problems is 309

Did not participate in 911 rescue is 110 (309+110) =419

participated no risk 793 + participated with moderate/severe risk 309 = 1102

did not participate no risk 441+ participate with moderate severe risk 110 =551

total 1102+551=1653

Question 1:

State the appropriate hypotheses for the chi-square test for independence in this case.

Now you will check whether the conditions for the chi-square test are met. You’ll need to first launch the actual research report and read the last paragraph on page iii of the introduction (starting with the “The study was fully funded…”)

Instructions

Click on the link corresponding to your statistical package to see instructions for completing the activity, and then answer the questions below.

R | StatCrunch | Minitab | Excel 2007 | TI Calculator

Question 2:

Does the data meet the conditions for the chi-square test?

Instructions

Click on the link corresponding to your statistical package to see instructions for completing the activity, and then answer the questions below.

R | StatCrunch | Minitab | Excel 2007 | TI Calculator

Question 3:

State your conclusion in context. Also explain what the P-value means as a conditional probability based on the null hypothesis.