The percentage of runners having times less than 14.4 sec is 0.15%. Then the correct option is A.
<h3>What is normal a distribution?</h3>It is also called the Gaussian Distribution. It is the most important continuous probability distribution. The curve looks like a bell, so it is also called a bell curve.
The times of all 15-year-olds who run a certain race are approximately normally distributed with a given mean (μ) = 18 sec and standard deviation (σ) = 1.2 sec.
The runners have times less than 14.4 sec.
The z-score is a numerical measurement used in statistics of the value's relationship to the mean of a group of values, measured in terms of standards from the mean.
Then the Percentage will be
More about the normal distribution link is given below.