The mean GPA of students in a
neighboring school is 3.1 with a
standard deviation of 0.3. What
percent of students have a GPA
higher than 3.1? *

Respuesta :

Answer:

50% of students have a GPA  higher than 3.1.

Step-by-step explanation:

We are given that the mean GPA of students in a  neighboring school is 3.1 with a  standard deviation of 0.3.

Assuming that the data follows normal distribution.

Let X = GPA of students in a  neighboring school

So, X ~ Normal([tex]\mu=3.1,\sigma^{2} =0.3^{2}[/tex])

The z score probability distribution for normal distribution is given by;

                               Z  = [tex]\frac{X-\mu}{\sigma}[/tex]  ~ N(0,1)

where, [tex]\mu[/tex] = population mean GPA = 3.1

           [tex]\sigma[/tex] = standard deviation = 0.3

Now, the probability that the students have a GPA  higher than 3.1 is given by = P(X > 3.1)

        P(X > 3.1) = P( [tex]\frac{X-\mu}{\sigma}[/tex] > [tex]\frac{3.1-3.1}{0.3}[/tex] ) = P(Z > 0) = 0.50

The above probability is calculated by looking at the value of x = 0 in the z table which has an area of 0.50.

Therefore, 50% of students have a GPA  higher than 3.1.