in an all boys school, the heights of the student body are normally distributed with a mean of 71 inches and…

in an all boys school, the heights of the student body are normally distributed with a mean of 71 inches and a standard deviation of 3 inches. what percentage of the students are between 72 and 79 inches tall, to the nearest tenth?

in an all boys school, the heights of the student body are normally distributed with a mean of 71 inches and a standard deviation of 3 inches. what percentage of the students are between 72 and 79 inches tall, to the nearest tenth?

Answer

Explanation:

Step1: Calculate z - scores

The z - score formula is $z=\frac{x-\mu}{\sigma}$, where $\mu$ is the mean, $\sigma$ is the standard deviation, and $x$ is the value from the data set. For $x = 72$: $z_1=\frac{72 - 71}{3}=\frac{1}{3}\approx0.33$ For $x = 79$: $z_2=\frac{79 - 71}{3}=\frac{8}{3}\approx2.67$

Step2: Use the standard normal table

We want to find $P(0.33<Z<2.67)$. We know that $P(0.33<Z<2.67)=P(Z < 2.67)-P(Z < 0.33)$. From the standard - normal table, $P(Z < 2.67)=0.9962$ and $P(Z < 0.33)=0.6293$.

Step3: Calculate the probability

$P(0.33<Z<2.67)=0.9962 - 0.6293=0.3669$.

Step4: Convert to percentage

To convert the probability to a percentage, we multiply by 100. $0.3669\times100 = 36.7%$ (to the nearest tenth)

Answer:

$36.7%$