2.2.3 - Shape

Quantitative variables are often discussed in terms of their shape. Both dotplots and histograms can be used to interpret a distribution's shape. A distribution may be described in terms of symmetry and skewness.

Symmetrical Distribution

A distribution that is similar on both sides of the center.

Symmetrical Distribution

Normal Distribution

One specific type of symmetrical distribution. This is also known as a bell-shaped distribution. 

Normal Distribution

Skewed
A distribution in which values are more spread out on one side of the center than on the other.
Right Skewed

A distribution in which the higher values (towards the right on a number line) are more spread out than the lower values. This is also known as positively skewed.

Right Skewed Distribution

Left Skewed

A distribution in which the lower values (towards the left on a number line) are more spread out than the higher values. This is also known as negatively skewed.

Left Skewed Distribution