Answer:
= 15.866%
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%