Answer: The correct option is the THIRD GRAPH. Its image is attached below.
Step-by-step explanation: We are given to select the graph that has a rate of change equal to [tex]\frac{1}[3}[/tex] in the interval between 0 and 3 on the X-axis.
We know that
the rate of change of a function f(x) in the interval x = a to x = b is given by
[tex]R_c=\dfrac{f(b)-f(a)}{b-a}.[/tex]
FIRST GRAPH :
Here the value of the function at the points x = 0 and x = 3 are given by
[tex]f(0)=2,~~f(3)=4.[/tex]
So, the rate of change in the interval [0, 3] will be
[tex]R_c=\dfrac{f(3)-f(0)}{3-0}=\dfrac{4-2}{3-0}=\dfrac{2}{3}\neq \dfrac{1}{3}.[/tex]
This option is NOT correct.
SECOND GRAPH :
Here the value of the function at the points x = 0 and x = 3 are given by
[tex]f(0)=0,~~f(3)=6.[/tex]
So, the rate of change in the interval [0, 3] will be
[tex]R_c=\dfrac{f(3)-f(0)}{3-0}=\dfrac{6-0}{3-0}=\dfrac{6}{3}=2\neq \dfrac{1}{3}.[/tex]
This option is NOT correct.
THIRD GRAPH :
Here the value of the function at the points x = 0 and x = 3 are given by
[tex]f(0)=\dfrac{3}{2},~~f(3)=\dfrac{5}{2}.[/tex]
So, the rate of change in the interval [0, 3] will be
[tex]R_c=\dfrac{f(3)-f(0)}{3-0}=\dfrac{\dfrac{5}{2}-\dfrac{3}{2}}{3-0}=\dfrac{2}{2\times3}=\dfrac{1}{3}.[/tex]
This option is CORRECT.
FOURTH GRAPH :
Here the value of the function at the points x = 0 and x = 3 are given by
[tex]f(0)=\dfrac{1}{2},~~f(3)=0.[/tex]
So, the rate of change in the interval [0, 3] will be
[tex]R_c=\dfrac{f(3)-f(0)}{3-0}=\dfrac{0-\dfrac{1}{2}}{3-0}=-\dfrac{1}{6}\neq \dfrac{1}{3}.[/tex]
This option is NOT correct.
Thus, the correct option is the THIRD GRAPH. Its image is attached below.