Question

Help please? Suppose you have a normally distributed set of data pertaining to a standardized test. The mean score is 500 and the standard deviation is 100. What is the z-score of 450 point score? 1.5 1 0.5 -0.5

Answer 1

The formula to calculate the z-score of a certain value is:

z = (x - (mean))/(standard deviation)

In this example, the x-value is 450, the S.D. is 100, and the mean is 500.

So, substitute these values into the formula.

z = (450-(500))/100
z=-50/100
z=-0.5

Therefore, the z-score is -0.5.