You should have seen that 0.50 is a plausible value for the true proportion of all 16- to 17-year-olds who have used their cell phones while driving. Does this prove that 0.50 is the true value?

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.