Answer:
1/3
Explanation:
The average rate of change of a function f(x) on an interval [a, b] is given by the formula ...
rate of change = (f(b) -f(a))/(b -a)
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For the given function and interval, this is ...
(log₂(4·8) -log₂(4·2))/(8 -2) = (5 -3)/(6) = 1/3
The average rate of change is 1/3.
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In the attached graph, the line between the points at the ends of the interval can be seen to have a rise of 1 for a run of 3. Its slope is 1/3.