Skip main navigation

Sigma Notation Part 1

.
16.9
Next I want to introduce you to the most common symbol you’re going to see in statistical formulas, sigma notation. Now, this might look intimidating. But it’s actually a really simple symbol. It’s a basic instruction that says add something up. That’s really all it means. Sigma means sum. So just add them up. Add up what? Whatever comes after the sigma. Usually we have parentheses after the sigma. And whatever is in those parentheses, we’re going to add up. It’s a really basic instruction. And it’s going to be really useful. I could put a variable in there. I could put a variable that’s been modified, like I might say square every score and add them up, et cetera.
55.2
But we won’t do that just yet. As a basic example, let’s say we’re going with our example of x representing age. So we’ve got these four individuals here with four different ages. So very basically, if I were to say, give me the sigma of x or the sum of the ages, just add them up. 30, 21, 59, and 45 add up to 155. And that’s really all there is to sigma notation. It looks intimidating. It looks really fancy. But it’s a very basic command that says add up whatever comes in those parentheses.
This article is from the free online

Essential Mathematics for Data Analysis in Microsoft Excel

Created by
FutureLearn - Learning For Life

Our purpose is to transform access to education.

We offer a diverse selection of courses from leading universities and cultural institutions from around the world. These are delivered one step at a time, and are accessible on mobile, tablet and desktop, so you can fit learning around your life.

We believe learning should be an enjoyable, social experience, so our courses offer the opportunity to discuss what you’re learning with others as you go, helping you make fresh discoveries and form new ideas.
You can unlock new opportunities with unlimited access to hundreds of online short courses for a year by subscribing to our Unlimited package. Build your knowledge with top universities and organisations.

Learn more about how FutureLearn is transforming access to education