Question

Chris obtains a z-score of +1.5. The standard deviation in the sample is 12 and Chris’s raw score is 78, so what is the sample’s mean?

Answer 1

From the link above:
In these case, the z-score is

\[ z={x-{\bar {x}} \over S}\]
where:

\( \bar {x}\) is the mean of the sample.
S is the standard deviation of the sample.