we will use the next formula to find the rate of change of the given interval
[tex]r=\frac{f(b)-f(a)}{b-a}[/tex]
in our case
a=-3
b=6
[tex]f(-3)=10\log (-3+4)+2=2[/tex]
[tex]f(6)=10\log (6+4)+2=12[/tex]
then we substitute the values in the formula
[tex]r=\frac{12-2}{6-(-3)}=\frac{10}{6+3}=\frac{10}{9}[/tex]
The average rate of change is 10/9=1.11
