The Variance How to calculate it

From Raw Data

The Variance and Standard Deviation

Example 1

From a Frequency Table

Formula to find the Variance

Example 2 - Question Calculate the variance for this set of data

Example 2 - Solution

Grouped Data Use the same formula but find your mid-points to make x values just as you did for the mean

Coding to find the Variance

How and why use coding?

Example 3 - Question

Example 3 Solution Set out your table first

Example 3 Solution Then do the calculations

Example 4