College

Three potential employees took an aptitude test, each with a different version. The scores are reported below:

- Tobias: Score = 84.5; Mean = 66.9; Standard Deviation = 11
- Kiersten: Score = 281.8; Mean = 261; Standard Deviation = 26
- Pierce: Score = 7.69; Mean = 7.2; Standard Deviation = 0.7

If the company has only one position to fill and prefers to hire the applicant who performed best on the aptitude test, which applicant should be offered the job?

Answer :

Answer:

Tobias should be offered the job.

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.

In this question:

The applicant with the highest z-score should be chosen.

Tobias:

Score of 84.5, in a version with mean 66.9 and standard deviation 11. His z-score is found when [tex]X = 84.5, \mu = 66.9, \sigma = 11[/tex]

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

[tex]Z = \frac{84.5 - 66.9}{11}[/tex]

[tex]Z = 1.6[/tex]

Kiersten:

Score of 281.8, in a version with mean 261 and standard deviation 26. His z-score is found when [tex]X = 281.8, \mu = 261, \sigma = 26[/tex].

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

[tex]Z = \frac{281.8 - 261}{26}[/tex]

[tex]Z = 0.8[/tex]

Pierce:

Score of 7.69, version with mean 7.2 and standard deviation 0.7. His z-score is found when [tex]X = 7.69, \mu = 7.2, \sigma = 0.7[/tex].

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

[tex]Z = \frac{7.69 - 7.2}{0.7}[/tex]

[tex]Z = 0.7[/tex]

Due to the higher z-score, Tobias should be offered the job.