Answer: The proportion that will qualify is 0.0314 or 3.14%.
First, we need to find the z-score of a time of 128 seconds. To do this, we find the difference of the mean and score and divide by the standard deviation.
(128 - 141) / 7 = -1.86
Now, use a standard normal distribution table to determine the percent below a z-score of -1.86. That value is 0.0314 or 3.14%.
