Skewness is a key figure in statistics. Based on asymmetry, it analyses the extent to which a frequency distribution deviates from the normal distribution. The normal distribution has a skewness of zero and is therefore symmetrical. If a frequency distribution has a skewness greater than zero, it is a right-skewed (left-sloping) distribution, which means that the curve is flatter on the right than on the left. However, if the skewness of a curve is below zero, it is a left-skewed (right-steep) distribution and the curve is flatter on the left than on the right.