In nearly all planning situations there will be variability. With some reasonable ease we may calculate mean or average of whatever it is we are … Read More

Is there a difference between two groups? That’s the question that leads to decisions in public policy, marketing, and medicine. Does a new drug work … Read More

So you do a split test on your site: one page has a red button, another page has a green button. Your conversion rate was … Read More

If you’ve been around finance long enough, you’ll probably recall that your data should be “well behaved” according to the Bell Curve. But that’s not … Read More

The old saying goes that numbers like averages can be misleading, which isn’t entirely accurate. Averages is simply poor storytellers. They present you with a … Read More

The thing about outliers is you have nine values that appear completely typical, then there’s one that doesn’t even come close. Maybe that’s not an … Read More

There’s a way for you to use statistics to find outliers in your data: it’s called the modified z-score. It resolves the push-pull of suspicion … Read More

Sometimes there’s one number in the middle of all these numbers and they looks like a perfectly good set of data. Except then you see … Read More

You have an 84 on a math exam and a 710 on a verbal section. One is big, the other is little. Which one indicates … Read More

The measure of standard deviation is what you typically learn first; it show up everywhere in textbooks. Another way to do this is with a … Read More