Consider the following.

Suppose a consumer group compares the weight of a car and its fuel mileage. They find that a car weighing 2,300 pounds has a fuel mileage rating of 24 miles per gallon (mpg) and that the fuel mileage decreases by 5.3 mpg for each successive 1,000 pounds added to the car's weight.

Let x represent the car's weight in thousands of pounds, and let y represent the fuel mileage rating in mpg.

Identify the marginal change b and the given ordered pair (x₁, y₁).

b =

(x₁, y₁) = ( )

Write a equation in point-slope form using the given ordered pair (x₁, y₁) for the fuel mileage ratings of a car from x = 2,000 pounds to x = 4,000 pounds.