# statistics 6

Suppose, in a study was conducted to see if receiving speeding violation and car phone use were independent. In this study, 755 drivers were surveyed. Out of 755, 70 had a speeding violation and 685 did not; 305 were car phone users and 450 were not.
Car phone user                            Not a car phone user                             Total:
Received speeding violation                    38                                                        32                                                  70

Did not received speeding violation        267                                                    418                                                685

Total:                                                               305                                                    450                                              755
Use a 5% level of significance, to see if receiving speeding violation is independent of car phone use?

EXPECTATIONS
– Draw graphs and charts when appropriate and necessary to demonstrate your reasoning! Label all graphs and charts!
– Display formulas. Write complete sentences to summarize your conclusions.
– If use any table values, clearly state which tables you used (e.g. Table A-2, etc.).
-Attach excel output when appropriate or necessary (e.g. a scatterplot, etc.)

HYPOTHESIS TESTING QUESTIONS
Your work for all statistical hypothesis testing questions should include the following:
1. Established Ho and Ha.
2. Summary statistics (either computed or given in the problem)
3. The name of the test (e.g. 2sampleTtest or T-test about correlation, etc.)
4. A formula to compute a test statistic (e.g. 1Prop-Z test statistic, etc.)
5. A p-value of the test and/or a critical value from a statistical table.
6. Clearly state the decision rule you use the reach a conclusion. (You may have to sketch a graph to show rejection regions.) Do you “Reject Ho” or do you “Fail to Reject Ho”?
7. State your conclusion in plain language. Use complete sentences.