Final answer:
The rate of change of the cost in dollars with respect to the number of miles is 1.75.
Step-by-step explanation:
The rate of change of the cost in dollars with respect to the number of miles can be determined by finding the slope of the function.
In the given function, y = 2.25 + 1.75x - 1, the coefficient of x represents the slope of the function.
The slope is 1.75, which means that for every additional mile, the cost in dollars increases by $1.75.