A normal distribution has mean $\mu$=60 and standard deviation $\sigma$=20 . Find and interpret the z-score for x=90.
A) z=-1.50 : a value of 90 is 1.50 standard deviations below the mean.
B) z=10 : a value of 90 is 10 standard deviations below the mean.
C) z=1.50 : a value of 90 is 1.50 standard deviations above the mean.
D) z=2.25 : a value of 90 is 2.25 standard deviations above the mean.

Question

Quizplus · Accepted Answer

To find the z-score, we use the formula:

z = (x - mean) / standard deviation

Plugging in the values given, we get:

z = (90 - 60) / 20 = 1.50

So the answer is option C, which states that a value of 90 is 1.50 standard deviations above the mean.

A Normal Distribution Has Mean μ\muμ =60 and Standard Deviation σ\sigmaσ =20 Find and Interpret the Z-Score for X=90

A Normal Distribution Has Mean $\mu$ =60 and Standard Deviation $\sigma$ =20 Find and Interpret the Z-Score for X=90