Two datasets has similar standard deviations, yet one is relatively stable and the other is chaotic. Dispersion metrics in raw form let you down. They … Read More

You collect data to find the truth. It comes from the data you collected. It come from the sample mean. The standard error of the … Read More

You’ve got two sets of data in your spreadsheet. One group has taken new medication; another group has taken a placebo. The average outcome is … Read More

The mean provides some sort of refuge: a few lab readings or quiz scores in your hand, and the average seem to represent center. It … Read More

Many folks compute it. Not many love to look at it. Variance is one of those stats. You might think of it as a vague … Read More

There’s a spreadsheet with fifty test scores. There’s dread. Then there’s the mean, at the top of the page. But the mean masks what happened. … Read More

Data sorting isn’t merely about ordering values in ascending order; that part’s easy enough. Trouble arises when you sort a list into quarters. How do … Read More

Looking at a string of weekly sales numbers, you’d see a mess. But a good analyst would see something else: a story that hides behind … Read More

This means you will see, for instance, that averaging your customers’ ratings may skew results if one angry customer drags rating down from a solid … Read More

If you drove sixty miles per hour to work and forty miles per hour back home, your intuitive arithmetic average would say you went fifty … Read More