Now use the One Proportion applet to create an interval of plausible values with 95% confidence for the population proportion of drivers 16 to 17 who have ever talked on a cell phone while driving using the 2SD method with π = 0.50.

a. What is the interval?
b. How does your confidence interval using the 2SD method and π = 0.50 compare to the confidence interval of plausible values you found in Question 18?
c. Without doing extensive work, find the 95% confidence interval for the proportion of drivers aged 16 to 17 who have NOT talked on the cell phone while driving.

Let’s use our 3S strategy to help us investigate how much evidence the sample data provide to support our conjecture that a majority of 16- to 17-year olds have talked on their cell phone while driving.