Answer
$3.5$
Work Step by Step
The average rate of change of $f(x)$ over the interval $[a, b]$ is $\displaystyle \frac{f(b)-f(a)}{b-a}$
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Given the interval $[-1,1]$ and the table,
a=$-1,\ \quad f(-1)=-0.5$
b=$1,\ \quad f(1)=6.5$
$\displaystyle \frac{f(b)-f(a)}{b-a} =\displaystyle \frac{6.5-(-0.5)}{1-(-1)}$
$=\displaystyle \frac{6.5+0.5}{1+1}=\frac{7}{2}=3.5$
(no units)
