Given
40, 60, 65, 70, 80
Procedure
In the formula above, u represents the mean of the data points, x is the value of an individual data point, and N is the total number of data points.
u=(40+60+65+70+80)/5
u=63
[tex]\begin{gathered} (x-u)^2= \\ (40-63)^2=529 \\ (60-63)^2=9 \\ (65-63)^2=4 \\ (70-63)^2=49 \\ (80-63)^2=289 \end{gathered}[/tex][tex]\sum ^{}_{}(x-u)^2=880[/tex][tex]\sigma^2=\frac{\sum ^{}_{}(x-u)^2}{N}=\frac{880}{5}=176[/tex]
The variance is 176
