A tire manufacturer is preparing to make a batch of tires. The function g(t) computes the amount of rubber (measured in pounds) needed to produce t tires, and f(x) computes the cost (measured in dollars) of obtaining x pounds of rubber. (a) What are the units of the slope of the secant line of g(t)? Think about the units of the numbers you use to find the slope. (b) What are the units of the slope of the secant line of f(x)? (c) What are the units of the slope of the secant line of (f g)(x)?