The ages of students in a school are normally distributed with a mean of 16 years and a standard deviation of 1 year. Using the empirical rule, approximately what percent of the students are between 14 and 18 years old?

Respuesta :

Answer:

95% of students are between 14 and 18 years old

Step-by-step explanation:

First we calculate the Z-scores

We know the mean and the standard deviation.

The mean is:

[tex]\mu=16[/tex]

The standard deviation is:

[tex]\sigma=1[/tex]

The z-score formula is:

[tex]Z = \frac{x-\mu}{\sigma}[/tex]

For x=14 the Z-score is:

[tex]Z_{14}=\frac{14-16}{1}=-2[/tex]

For x=18 the Z-score is:

[tex]Z_{18}=\frac{18-16}{1}=2[/tex]

Then we look for the percentage of the data that is between [tex]-2 <Z <2[/tex] deviations from the mean.

According to the empirical rule 95% of the data is less than 2 standard deviations of the mean.  This means that 95% of students are between 14 and 18 years old