# GMAT Statistics: How Standard Deviation is Tested

Students sometimes freak out a bit when they learn that the GMAT tests statistics. Perhaps it’s because they still have nightmares about their college stats class and all those crazy greek letters, complex math equations, and endless regression analyses. If that’s you, fear not! The good news is that the statistics tested on the GMAT is pretty basic. You have to know basic definitions and applications of terms like * mean, median, mode, and range*. You should even know a little something about variance and

**how variance is tested on the GMAT**. And of course,

*will likely come up at some point on the GMAT quantitative section.*

**standard deviation**### Standard Deviation on the GMAT

You should expect that you’ll need to know *something* about standard deviation on the GMAT, but what you won’t have to do is actually calculate the standard deviation of a set of numbers using that long and annoying formula you probably had to memorize at one point during your academic career. Instead, you’ll simply need to apply what you know about standard deviation to certain types of questions.

Let’s start with a simple, basic definition that will serve you well:

**Standard Deviation is a measure of the spread around the mean (average) of a set of numbers.** The more spread out a set of numbers, the larger the standard deviation; the tighter a set of numbers are to their average, the lower the standard deviation.

Okay, so that’s all well and good. But how do you use that understanding to get right answers on the GMAT? For a full tutorial on everything you’ll need to know about statistics on the GMAT, check out our video lesson on **“GMAT Arithmetic and Statistics.”** In the meantime, watch this video (below) where I go step-by-step through how to answer a sample GMAT problem solving question involving standard deviation and teach the relevant statistical understanding along the way: