Question

you score a 65% on your ap statistics exam and a 78% on your economics exam. the AP statistics scores were normally distributed with an average of 60% and a standard deviation of 6%. the economics scires were also normally distributed with an average of 75% and the standard deviation of 2.5%. In which class did you perform better relative to the class average? be sure to justify your answer​

Answer 1

You performed better relative to the class average in your economics class.

Explanation:

There are two classes.

AP statistics class and Economic class

Using the z score formula,

z = (x-μ)/σ, where

x is the raw score

μ is the population mean

σ is the population standard deviation.

In the AP statistics class, you scored a percentage of 65%. The class average was 60%

x is the raw score = 65%

μ is the population mean = 60%

σ is the population standard deviation = 6%

z = (x-μ)/σ

z = (65 - 60)/6

z = 5/6

z = 0.8333333333

In the Economics classes, you scored a percentage of 78% with a class average of 75%

x is the raw score = 78%

μ is the population mean = 75%

σ is the population standard deviation = 2.5%

z = (x-μ)/σ

z = (78 - 75)/2.5

z = 3/2.5

z = 1.2

Comparing the z score of both exams taken from different classes,we can see that your z score was higher in the Economics class compared to the A.P statistics class.

Therefore, you performed better relative to the class average in your economics class.