2. (10 points) Test scores on a
standardized test are normally
distributed, with a mean of 50
and a standard deviation of 5.
Standard deviations
34%
34%
13.5%
13.5%
0.1% 2.4%
2.4% 0.1%
a.) Label the horizontal axis of the normal distribution above with the appropriate test scores.
b.) If 5000 students took this test, what percentage would have scored 40 or higher?
How many of the 5000 students would score 40 or higher?
c.) If 5000 students took this test, how many would have scored 40 or lower?
d.) What percentile ranking would a test score of 45 receive? (You can round to the nearest whole number).
What does this percentile mean in everyday language?
e.) One of your students took this test and scored a 65, and her parents are quite upset at what they
perceive to be a very low score. What do you say to the parents to put this score into context?