The average is 0.3333.
Mean
Mean is simply defined as the average of the given set of numbers. The mean is considered as one of the measures of central tendencies in statistics. The mean is said to be an arithmetic mean. It is the ratio of the sum of the observation to the total number of observations.
Given
A graph is shown depth versus time.
To find
The average rate of change for the depth of the river, measured as feet per hour, between hour 9 and hour 18.
How to get the average rate of change for the depth of the river, measured as feet per hour, between hour 9 and hour 18?
It is the ratio of the sum of the observation to the total number of observations.
So the ratio of depth to time is average.
The difference in depth is 3 feet.
And time duration is 9 hours
Then the average will be
[tex]\rm Average = \dfrac{Difference\ in\ depth}{time duration} \\\\Average = \dfrac{3}{9} \\\\Average = \dfrac{1}{3} \\\\Average = 0.333[/tex]
The average is 0.3333.
More about the mean link is given below.
https://brainly.com/question/2426692