Exercise 11 Page 715

We are given a table that shows the speeds of eight roller coasters in the United States.

	Roller Coaster Speeds
Coaster	Dodonpa	Kingda Ka	Millennium	Phantom's Revenge	Steel Dragon $2000$	Superman: The Escape	Top Thrill Dragster	Tower of Terror
Speed (mph)	$107$	$128$	$93$	$82$	$95$	$100$	$120$	$100$

We are asked to find the mean absolute deviation of the set of data. First, we need to find the mean of the data set. Let's sum all the speeds! Now to calculate the mean, let's divide the sum by the number of the roller coasters which is $8.$ We found the mean! Next, let's find the distance of each value from the mean. The distance is equal to the absolute value of the difference between each value in the data set and the mean.

Speed	$|\text{Mean}-\text{Speed}|$	Distance from the Mean
$107$	$|103.125-107|$	$3.875$
$128$	$|103.125-128|$	$24.875$
$93$	$|103.125-93|$	$10.125$
$82$	$|103.125-82|$	$21.125$
$95$	$|103.125-95|$	$8.125$
$100$	$|103.125-100|$	$3.125$
$120$	$|103.125-120|$	$16.875$
$100$	$|103.125-100|$	$3.125$

The mean absolute deviation is the mean of all the distances. To find it, we will first sum all the distances. Now let's divide the sum by the number of the distances, which is $8.$ We found that the mean absolute deviation is equal to $11.41.$ This means that the average distance between each roller coaster speed and the average roller coaster speed is equal to about $11.41$ miles per hour.