STAT-2300 Lecture 5: Describing Spread

• School: Clemson University
• Department: Statistics
• Course: STAT-2300
• Professor: Erwin Walker

Document Summary

While the shape and measure of center can describe a lot about a distribution, they do not indicate the degree to which the data is spread out. The amount of dispersion is described using the spread, which can show how two or more distributions may have the same shape and center but look very different. For example, looking at these two distributions, they both appear symmetric and bell shaped and since their peaks are in the same spot, they both have the same median and therefore the same mean given their shape. The thing that makes them different is the spread. The red line has much more variation within the data, making it look much different than the purple line, which has very little variation. The range is the difference between the largest and the smallest observations. It is the simplest and easiest measure of spread to compute, but it is affected severely by outliers. (cid:1853)(cid:1866)(cid:1859)(cid:1857)=(cid:1865)(cid:1853)(cid:1865)(cid:1873)(cid:1865) (cid:1865)(cid:1866)(cid:1865)(cid:1873)(cid:1865)