Answer:
(a) The rate of change for the money earned, measured as dollars per delivery, between 0 and 2 deliveries is $2.
(b) The rate of change is the same between the two time intervals.
Step-by-step explanation:
The rate of change for a variables based on another variable is known as the slope.
The formula to compute the slope is:

(a)
Compute the rate of change for the money earned, measured as dollars per delivery, between 0 and 2 deliveries as follows:
For, <em>x</em>₁ = 0 and <em>x</em>₂ = 2 deliveries the money earned are <em>y</em>₁ = $5 and <em>y</em>₂ = $9.
The rate of change for the money earned is:


Thus, the rate of change for the money earned, measured as dollars per delivery, between 0 and 2 deliveries is $2.
(b)
Compute the rate of change for the money earned, measured as dollars per delivery, between 2 and 4 deliveries as follows:
For, <em>x</em>₁ = 2 and <em>x</em>₂ = 4 deliveries the money earned are <em>y</em>₁ = $9 and <em>y</em>₂ = $13.
The rate of change for the money earned is:


The rate of change for the money earned, measured as dollars per delivery, between 2 and 4 deliveries is $2.
Compute the rate of change for the money earned, measured as dollars per delivery, between 6 and 8 deliveries as follows:
For, <em>x</em>₁ = 6 and <em>x</em>₂ = 8 deliveries the money earned are <em>y</em>₁ = $17 and <em>y</em>₂ = $21.
The rate of change for the money earned is:


The rate of change for the money earned, measured as dollars per delivery, between 6 and 8 deliveries is $2.
Thus, the rate of change is the same between the two time intervals.