If you have a set of measurement scores on different measures using Z-Scores you can tell how the scores are placed in their distributions. Then you can compare them. Knowing the mean and SD of a distribution that is reasonably normal allows you to determine the percentile rank of that score.

Now, let’s go to our final question.
Curving a test means that a professor marks you on a Z-Score basis. If the mean is high do you want the test curved? Think about it.