Answer
Variance:1017.7 Standard deviation:31.9 Range:79.
Work Step by Step
The mean can be counted by summing all the data and dividing it by the number of data: $\frac{9+23+25+88+12+19+74+77+76+73+78}{11}=50.36$: $\mu=50.36.$ Variance=$\frac{\sum (x-\mu)^2}{n}=\frac{(11-50.36)^2+(3-50.36)^2+...+(2-50.36)^2}{11}=1017.7.$ Standard deviation=$\sqrt{variance}=\sqrt{1017.7}=31.9$ Range=maximum value-minimum value=88-9=79$.
