Which measure of variation should you use to describe two data sets that are both symmetric?

Z-Score

Example:

In this problem, on a math test the mean score is 82 with a standard deviation of 3. A passing score is 70 or greater. Choose a passing score that you would consider to be the outlier. Since the given options are not provided we can hypothesize that the possible score or outlier in this distribution is any number exceeding the z score of 3 or above given that the standard deviation is 3 and a mean of 82.