The following problems are intended to help you continue working with formulae and concepts pertaining to contingency tables (bivariate frequency tables).
Results on seat belt usage from the 2003 Youth Risk Behavior Survey were published in a USA Snapshot on January 13, 2005. The following table outlines the results from the high school students who were surveyed in the state of Nebraska. They were asked whether or not they rarely or never wear seat belts when riding in someone else's car (Johnson & Kuby, 2007).
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Gender
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Female
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Male
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Total
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Rarely or Never uses seat belt
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208
|
324
|
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Usually or Always uses seat belt
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1217
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1184
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|
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Total
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1. Fill in the remainder of the table (find the totals). How many total students were surveyed for this study?
2. What are the two variables in this study? Which one is the independent variable and which is the dependent variable? How do you know? Explain briefly.
3. What percentage of women rarely or never use their seatbelts? Please show your work.
4. What percentage of men rarely or never use their seatbelts? Please show your work.
5. Does it appear that there is a significant difference in the percentage of men and women who rarely or never wear their seatbelts? Explain.
6. What percentage of women usually or always use their seatbelts? Please show your work.
7. What percentage of men usually or always use their seatbelts? Please show your work.
8. Does it appear that there is a significant difference in the percentage of men and women who usually or always wear their seatbelts? Explain.
9. Based on your answers above, and the results of a hypothesis test for the contingency table above, does it appear that the independent variable affects the dependent variable? Explain
10. Interpret the results in the context of the problem.