# Basic Statistics

## Mean

The average of a set of values. Add all values in a set together and divide by the number of values in the set.

## Median

The value at the center of a set of values.

### Odd-numbered Sets

In odd-numbered sets choose the value in the middle.

### Even-numbered Sets

In even-numbered sets the mean of the two middle values is the Median.

## Mode

The Mode is the most common value in a set. If the set has more than one Mode calculate the average of all Mode values.

## Range

The difference of the highest and lowest values in a set.

## Minimum

The lowest value in a set.

## Maximum

The highest value in a set.

## Count

The amount of values in a set.

## Sum

The total of all values in a set.

# Intermediate Statistics

## Standard Deviation (Sigma)

A representation of how dispersed the values in a set of data are.

## Standard Error

An estimate of the Standard Deviation as samples change within the same population. The Standard Error equals the Standard Deviation divided by the square root of the sample size.

## Variance

How spread out from the Mean values are in a set. Higher Variance values indicate that values in a set are more dispersed.

## Skewness

How asymmetrical a data set is, rather than being normally distributed. A zero skew indicates the tails of a distribution are even at the Mean.

## Kurtosis

How sharp the peak of a distribution curve is.

• 3: Normal distribution peak
• Less than 3: Flatter peak
• More than 3: Sharper peak