Answer:
The variance is of 8
Explanation:
To find the variance and the standard deviation, first we need to find the mean.
Mean:
Sum of all values divided by the number of values. So

The standard deviation is of 2.83
Variances:
Sum of the difference squared between each value and the mean, divided by the number of values. So
![V = ((78-72.67)^2+(72-72.67)^2+(68-72.67)^2+(73-72.67)^2+(75-72.67)^2+(69-72.67)^2+(74-72.67)^2+(73-72.67)^2+(72-72.67)^2)/(9) = 8]()
The variance is of 8
Standard deviation:
Square root of the variance. So

The standard deviation is of 2.83