Question

At a local high school, GPA's are normally distributed with a mean of 2.9 and standard deviation of 0.6. What is the GPA of the highest 2.5% of the students?

Answer 1

Explanation:

Highest 2.5% means 97.5 are below ( .9750)

look at + z-score table for this number

to find the corresponding z-score of 1.96 ( 1.96 Standard deviations ABOVE the mean of 2.9)

so the GPA in question is

2.9 + 1.96 * .6 = 4.076 GPA (round as necessary)

Looking at the following Bell Curve graph you can see this is true:

Answer 2

1.96*(. 6) + 2.9 = 4.1

Explanation:

hope this helps