The following are true of mean absolute deviation:

• It is calculated by averaging the absolute value of the differences between each data point and the mean value of the data set.


• It is a measure describing the variability of a data set.


• A data set has less variability when the mean absolute deviation is closer to zero.

Video Transcript (PDF)

The amounts of money raised by each homeroom selling tickets to the eighth-grade dance are shown below.

HR	Amount Raised
801	$88
802	$116
803	$94
804	$108
805	$112
806	$124

Each homeroom raised an average of $107 selling tickets to the dance.