One Plus One Is How Many?

Statistics are valuable for analysis and measurement but I tend to be a skeptic. When I hear a statistic quoted I want to know if it is in fact true. If it is true, I want to understand the context of the statistic, how it was gathered, and what it really means.

It is very easy to find an isolated statistic to support almost any position. It is also easy to misunderstand or misinterpret a statistic and then to perpetuate the resulting misinformation. And it is easy, perhaps too easy, to toss out a statistic in an attempt to add credibility to an objection.

Here is a brief refresher of some basics of statistical analysis:

Mean or Average--To find the mean of a set of numbers sum the values and divide by the number of values.

100+77+93+145+133+86+112=746

Divide 746 by the number of values in the set (7) to find the mean/average which is 107.

Median--The median is the middle value in the set of numbers when ordered by rank.

77, 86, 93, 100, 112, 133, 145 The median is 100.

A median is used when a value at one end or the other of the ranking would skew the average either up or down.

Mode--The most frequently occurring value in a set of numbers.