In one city,police estimate that 79% of drivers wear their seat belts.They set up a safety roadblock and they stop drivers to check for seat belt use.If 150 drivers are stopped,is it appropriate to use a normal model to approximate the distribution of the number whose seat belt is not buckled?

Question

Quizplus · Accepted Answer

To determine if a normal model can be used to approximate the distribution of the number of drivers whose seat belt is not buckled, we need to check if both np and nq are greater than or equal to 10.

np = 150 x (1 - 0.79) = 31.5
nq = 150 x 0.79 = 118.5

Both np and nq are greater than or equal to 10, so a normal model can be used to approximate the distribution.

The mean of the distribution is μ = np = 31.5, and the standard deviation is σ = √(npq) = √(31.5 x 0.21) = 4.99.

Therefore, the appropriate choice is D, which states that a normal model with μ = 31.5 and σ = 4.99 can be used to approximate the distribution.

In One City,police Estimate That 79% of Drivers Wear Their