A driver’s reaction time to visual stimulus is normally

Solution:

Step 1 of 3:

We have the mean of 0.4 seconds and a standard deviation of 0.05 seconds.

1. The claim is to find the probability that a reaction requires more than 0.5 seconds.

Then P(X > 0.5) = 1 - P(z <  )

                      = 1 - P(z < 2)

                      = 1 -  

                     = 1 - 0.9772 ( from the table of area under normal curve)

                     = 0.0228

Hence, the probability that a reaction requires more than 0.5 seconds is 0.0228.