Answer:
Part 1)

Part 2) The rate of change is

Part 3) The initial value is $3.5
see the attached figure
Explanation:
Part 1) Find the equation of the line
Observing the graph
Identify the points (0,3.5) and (1,6)
calculate the slope

Find the equation of the line
--->equation of the line into slope intercept form
we have

substitute

Part 2) Find the rate of change
we know that
The rate of change of the graph is equal to the slope of the line
the slope of the line is

therefore
The rate of change is

Part 3) Find the initial value
we know that
The initial value of the function is the y-intercept, is the value of y when the value of x is equal to zero
In this problem is the cost when the distance is equal to zero
The y-intercept is the point (0,3.5)
therefore
The initial value is $3.5