Question

myopenmath.comPractice E5 - Summer 2021 - Elementary Statistics (STAT-1401-03F)MyOpenMathPractice E5Score: 2/101/5 answeredQuestion 1<>The results of a common standardized test used in psychology research is designed so that the populationmean is 150 and the standard deviation is 30. A subject earns a score of 138. What is the Z-score for this rawscore?Z-score =

Answer 1

To calculate the z-score for a given population mean, μ, and a given standard deviation, σ, we use the following equation:

$z=\frac{x-\mu}{\sigma}$

We know x = 138, μ = 150 and σ = 30, so we can just input that:

$z=\frac{138-150}{30}=\frac{-12}{30}=-0.4$

So the z-sorce of 138 in this test is -0.4.