Respuesta :
Answer:
Due to the higher z-score, Zach did better relative to his class.
Step-by-step explanation:
Z-score:
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
In this question:
Whoever had the higher z-score did better:
Zach:
Scored 67, mean of 54 and standard deviation of 7, so [tex]X = 67, \mu = 54, \sigma = 7[/tex].
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{67 - 54}{7}[/tex]
[tex]Z = 1.86[/tex]
Adam:
Scored 88, mean 97, standard deviation of 6, so [tex]X = 88, \mu = 97, \sigma = 6[/tex]
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{88 - 97}{6}[/tex]
[tex]Z = -1.5[/tex]
Who did better relative to their class?
Due to the higher z-score, Zach did better relative to his class.
