In one city, police estimate that 82% of drivers wear their seat belts. They set up a safety roadblock and they stop drivers to check for seat belt use. The police stopped 160 drivers.
Now that you've calculated the z-score. Use the Normal Model to estimate the probability that no more than 140 drivers will have on their seatbelts.
Use 2nd, Vars, Normalcdf, you will need to decide the lower and upper limits.
IF you need Upper Infinity use: 99
IF you need lower infinity use: -99
USE the Z-score from #21.
Enter your answer as a decimal rounded to three places.