In a study of high school students at least 16 years of age, researchers obtained survey results summarized in the accompanying table (based on data from "Texting While Driving and Other Risky Motor Vehicle Behaviors Among U.S. High School Students," by O'Malley, Shults, and Eaton, Pediatrics, Vol. 131, No.).
Drove When Drinking Alcohol?
Yes No
Texted While Driving 731 3054
No Texting While Driving 156 4564
According to this distribution, find the expected counts for the table and compute the degrees of freedom.
EXPECTED COUNTS
Drove when drinking alcohol?
Yes No
Texted while driving
No texting while driving
Df=
Use a 0.05 significance level to test the claim of independence between texting while driving and driving when drinking alcohol. Are those two risky behaviors independent of each other?
What type of test will you run?
(copy symbols from the top of the test as needed; your hypothesis can be written using phrases or a sentence if needed)
Set up the hypothesis: Ho: Ha:
Test Statistic:
P-value:
Conclusion: P-value .05, therefore we (reject/fail to reject) the null hypothesis.
There (is/is not) statistically significant evidence at the level that the two risky behaviors are dependent of each other.