What is dispersion?

December 22, 2008

You have been gathering data for your business. It could be daily sales figures; spend per customer; cost per job.

You are interested in the spread of the data from your business.

So what is dispersion?

It”s how data is dispersed, or spread.

The mean, median and mode give an indication of central tendency, dispersion gives an indication of spread.

Measures of spread include: range; mean absolute deviation, variance and standard deviation.

Read more.


Most people have an “above average” number of feet

August 30, 2008

What’s the average number of feet?

Most people have an above average number of feet

No, not two.

The answer is slightly less. Think about it.

The BBC News Magazine is running a really nice series on maths.

If the thought that nearly everyone can be below average makes no sense, you might be muddled by the middle.

“Average” is commonly used to mean something like “ordinary”, “typical”, “normal” or “what’s expected”. Above is good, below is bad.

Organisations can apply a range of techniques to analyse data effectively for business purposes. By using the mean, median and mode, businesses can analyse their sales and costs to make effective business decisions.

For example by knowing both the average (mean), median and mode of sales by outlet or division, they can compare effectively which areas of the business need action.

Relying on one average (such as the mean) can result in ineffective decisions as sometimes averages can be swayed by a few high figures as explained in the BBC article.

Photo source.