Answer
Variance:231.4 Standard deviation:15.2 Range:43.
Work Step by Step
The mean can be counted by summing all the data and dividing it by the number of data: $\frac{−15−18−32−21−9−32+11+2}{8}=−14.25$: $\mu=(-14.25).$ Variance=$\frac{\sum (x-\mu)^2}{n}=\frac{((-15)-(-14.25))^2+((-18)-(-14.25))^2+...+(2-(-14.25))^2}{8}=231.4.$ Standard deviation=$\sqrt{variance}=\sqrt{231.4}=15.2$ Range=maximum value-minimum value=$11-(-32)=43$.