Question

a certain data set has a standard deviation of 20 and a mean of 150. one of the values in the data set is 120, what is the z-score for this data point?

Answer 1

The z-score for this data point is -1.5

Explanation:

Mean = M = 150

Standard Deviation = S = 20

Value = x = 120

We find the z value,

`z = (x-M)/S\\z = (120 - 150)/20\\z = (-30)/20\\z=-3/2\\z=-1.5`

Hence the z value is z = -1.5