Percentiles are 100 equal groups into which a population can be divided according to the distribution of values. A percentile can be between 1 and 99 – whatever number you pick, X% should fall below […]

# Category: Stats

# Understanding Correlation

Tech target defines correlation as: “a statistical measure that indicates the extent to which two or more variables fluctuate together”. There are two major components to correlation: strength and type of correlation. Let’s look at […]

# Measures Of Variance

Variance is a key statistical topic. It lets us know how close to the mean the data is clustered. Consider, if 2 classes have a mean exam score of 40%; does that mean that all […]

# Normal Distribution And The Empirical Rule

A normal distribution looks a little bit like the below. It’s where the mean, median and mode are on top of one another. Remember in a previous article, we discussed Chebyshev’s theorem, which gave us […]

# Standard Normal Distributions Understood

We’ve discussed normal distributions in previous articles & today, we’re going to talk about standard normal distributions. By standardising distributions, we can compare two different distributions directly. Remember, a normal distribution has no skew; is […]

# Z Scores & Probability

When we look at a standard normal distribution, we see something like the below. Here, we have the mean at the highest point, the mean, median and mode on top of one another and we […]