Answer: the student's score closest to 91 percentile.
Explanation:
Since the scores on the standardized test are approximately normally distributed, we would apply the formula for normal distribution which is expressed as
z = (x - µ)/σ
Where
x = test scores.
µ = mean score
σ = standard deviation
From the information given,
µ = 480
σ = 90
If a student has a score of 600, then x = 600
For x = 600,
z = (600 - 480)/90 = 1.33
Looking at the normal distribution table, the probability corresponding to the z score is 0.91
the student's score closest to 91 percentile.