Chapter Three continued – Lack of Katey laptop
Why study dispersion?
- So we can see how spread out the data is.
- Difference between the largest and smallest number
Mean absolute deviation
- Arithmetic mean of the absolute values of the deviations from the arithmetic mean
o All values are used in the calculation
o It is easy to understand because it is the average of the deviations from the mean
o Major drawback is the use of absolute values
- Population variance is the arithmetic mean of the squared deviations from the population