Answer:
[tex]Z = 0.125[/tex]
Step-by-step explanation:
Z - score
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
Calculate the z-score for Tony's GRE quantitative reasoning score.
This is Z when [tex]X = 615, \mu = 600, \sigma = 120[/tex]
So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{615 - 600}{120}[/tex]
[tex]Z = 0.125[/tex]
