Suppose you look at the outline of a probability distribution and it appears bell shaped but you are not certain whether it is normal. You then estimate that the area under the outline curve (of the distribution) of a two sigma (two standard deviations) band centered around the mean is 85% of the total area under the outline curve, meaning that the band bounded by two standard deviations to the left of the mean and two standard deviations to the right of the mean has area roughly equal to 85% of the total area. 

Explain why this distribution would not be normal?