A standardized test has a mean of 88 and a standard deviation of 12. What is the score at the 90th percentile? Assume a normal distribution.
A) 90.00
B) 112.00
C) 103.36
D) 91.00

Question

Quizplus · Accepted Answer

Using the z-score formula, z = (x - μ) / σ, we know that for the 90th percentile, the area to the left of the score is 0.9. Using a standard normal distribution table, we can find the corresponding z-score to be approximately 1.28. Rearranging the formula, we get x = μ + z*σ = 88 + 1.28*12 = 103.36. Therefore, the score at the 90th percentile is 103.36.

A Standardized Test Has a Mean of 88 and a Standard