1.2 Measures of Variability

Question 1

Range

Answer 1

Difference between highest and lowest number

Question 2

Variance

Answer 2

The average of the spread differences from the mean.

The mean needs to be worked out, meaning the average needs to be calculated.
Then for each number, subtract the mean and square the result (the squared difference).

Question 3

Standard Deviation

Answer 3

A quantity that tells me how much the members of a group differ from the value of the group.

The mean needs to be worked out.
Then for each number, subtract the mean and square the result.
The next step is to work out the mean of those squared differences.
Take the square root.