Question

A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 460 seconds and a standard deviation of 40 seconds. Find the probability that a randomly selected boy in secondary school can run the mile in less than 368 seconds.

Answer 1

Answer:

The probability that a randomly selected boy in secondary school can run the mile in less than 368 seconds is P(X<368)=0.011.

Step-by-step explanation:

We have a normal distribution with mean 460 and standard deviation 40 to describe the time for the mile run in its secondary-school fitness test.

We have to calculate the probabiltiy that a randomly selected boy in secondary school can run the mile in less than 368 seconds.

To calculate this, we have to calculate the z-score for X=368:

$z=\dfrac{X-\mu}{\sigma}=\dfrac{368-460}{40}=\dfrac{-92}{40}=-2.3$

Then, we can calculate the probability:

$P(X$