Police estimate that in one city 83% of drivers wear their seat belts.They set up a safety roadblock,stopping cars to check for seat belt use.If they stop 30 cars during the first hour,what is the standard deviation of the number of drivers expected to be wearing their seat belts?
A)5.1
B)24.9
C)4.23
D)2.06
E)4.99

Question

Quizplus · Accepted Answer

The standard deviation for a binomial distribution is calculated using the formula √(n * p * (1-p)), where n is the number of trials (30 cars), and p is the probability of success (0.83 for wearing seat belts). Plugging in the values gives √(30 * 0.83 * 0.17) ≈ 2.06.

Police Estimate That in One City 83% of Drivers Wear