Measures of Central Tendency -- Mean, Median, Mode & Midrange
Arithmetic Mean (a.k.a. Average)
This video explains the difference between the formula for mean that you learned in elementary school -- sum divided by number of items -- and the crazy Stats version of the formula that has Greek symbols and craziness in it. And why is there a different version of the formula for samples and population?
Mean & Median on your Stats Calculator
This video shows you how to enter statistics data into your calculator and then how to get the stats you want out. It's super-easy, so don't be intimidated by all those buttons and menus!
You probably think you know all there is to know about median, but this being Stats class, there's so much more! This video covers the old-school median you know, as well as why it's a "resistant" measure of center. Good stuff!
I wish I could say that mode is different in Stats class than it was back in middle school. Nope! Although they do introduce a couple new terms -- bimodal and multi-modal -- so that's fun.
Midrange vs Trimmed Mean
These are a couple of fun measures that not every class covers, but which are actually kind of useful in real world situations. Once you know what midrange and trimmed means are, you'll start recognizing them when you see statistics on the internet and realize what games they're playing.
Calculating Mean From Frequency Table
This is a type of problem that's specific to Statistics class: being asked to find the mean of a data set when you don't actually have the data set, just a table with ranges on it. No problem, it's a straightforward step-by-step process to make this calculation, so let's get started!
Calculating Median From Frequency Table
Another fun frequency table problem type: being asked to find the median when you don't have anything to go from other than a frequency table.
Mode of a set (SAT)
This video explains how to identify the mode of a set of numbers. For easy problems, finding the mode is simple, but this video also covers the couple of curve balls that teachers (and the SAT) usually throw at you.
If you do not have an account, you should get one, because it is awesome! You can save a playlist for each test or each chapter, and save your "greatest hits" into a "watch right before the final" list (not that we recommend cramming, but when in Rome...)