The class average on a math test was 80.3 and the standard deviation was 5.7. What percentage of the class scored above a 86?

= 15.866%

Step-by-step explanation:

The class average on a math test was 80.3 and the standard deviation was 5.7.

What percentage of the class scored above a 86?

We solve using z score formula

z = (x-μ)/σ, where

x is the raw score = 86

μ is the population mean = 80.3

σ is the population standard deviation = 5.7

Hence:

z = 86 - 80.3/5.7

z =1

Probability value from Z-Table:

P(x<86) = 0.84134

P(x>86) = 1 - P(x<86) = 0.15866

Converting to Percentage

= 0.15866 × 100

= 15.866%

Therefore, the percentage of the class scored above a 86 is 15.866%