Suppose GRE Quantitative scores are normally distributed with a mean of 587 and a standard deviation of 152. A university plans to offer tutoring jobs to students whose scores are in the top 14%. What is the minimum score required for the job offer? Round your answer to the nearest whole number, if necessary.

Respuesta :

Answer:

The minimum score required for the job offer is 751.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

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.

In this problem, we have that:

[tex]\mu = 587, \sigma = 152[/tex]

A university plans to offer tutoring jobs to students whose scores are in the top 14%. What is the minimum score required for the job offer?

This is the value of X when Z has a pvalue of 1-0.14 = 0.86. So it is X when Z = 1.08.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.08 = \frac{X - 587}{152}[/tex]

[tex]X - 587 = 1.08*152[/tex]

[tex]X = 751[/tex]

The minimum score required for the job offer is 751.