A study sponsored by AT&T and the Automobile Association of America included the sample data in the following table

a. Compare the percentage of cell phone users who had an accident to the percentage of those who did not use a cell phone and had an accident. On the basis of these results, do cell phones appear to be dangerous?
b. Identify the null and alternative hypotheses for a test of the claim that having an accident is independent of cell phone use.
c. Find the expected value for each cell of the table by assuming that having an accident is independent of cell phone use.
d. Find the value of the  statistic for a hypothesis test of the claim that having an accident is independent of cell phone use.
e. Based on the result from part d and the size of the table, refer to Table 10.7 (on page 358) and determine what is known about the P-value.
f. Based on the preceding results, what can you conclude from the hypothesis test about whether the two variables (cell phone use and having an accident) are independent?
g. Is the conclusion from part f consistent with what is now known about cell phone use and driving?

Had accident in last year 23 46 Had no accident in last year 282 407 Cell phone user Not a cell phone user