In a study of high school students at least 16 years of age, researchers obtained the survey results summarized in the table below (based on data from "Texting While Driving and Other Risk Motor Vehicle Behaviors Among U.S. High School Students" by O'Malley, Shults, and Eaton, Pediatrics, Vol. 131, No.6).

	Irregular Seat Belt Use?
	Yes	No
Texted While Driving	1737	2048
Did not Text While Driving	1945	2775

1. How do I state the null and alternative hypotheses?

2. Assuming independence, how do I determine the expected frequencies for each of these variables?

3. How do I determine the value of the X² statistic?

4. Using a 0.05 significance level to test the claim of independence between texting while driving and irregular seat belt use. How can one determine if those two risky behaviors are independent?

5. How can I calculate the chi-square manually or using Excel.