Summary Statistics Basics(with diagrams)

Statistics Basics

**Important NOTE** ALWAYS ORDER YOUR DATA SETS!

Basic terms:
Mode: The most common occurring value in a data set
Median(Also known as -> Q2): The middle value in an ordered data set
Mean(Also known as -> x ): The average of the data set
Range: The difference between the largest and smallest number in a dataset



The five number summary(with box and whisker diagram):
1)Minimum Value
2)Lower quartile(Q1)
3)Median(Q2)
4)Upper quartile(Q3)
5)Maximum value

Box and Whisker Diagram:

, How to workout the range of a data set:

Range = Max Value - Min Value

How to workout the position of the median:

Median =


n: The number of elements in the data set

How to workout the lower and upper quartiles:

Lower quartile(Q1) =

Upper quartile(Q3) =


How to workout the interquartile range(IQR):

Interquartile range(IQR) = Q3 - Q1

How to workout the percentile:


Position of percentile =


The value below which a specific percentage of data elements lie