3. For each of the following questions, write at least one careful sentence that explains the meaning of the given derivative value, including correct units. (a) The cost, C in dollars, to build a new home is a function of s, the number of square feet constructed, given by C(s). Explain the meaning of C'(1850) = 220 in the context of building a house. (b) The rate of fuel efficiency, F (in miles per gallon), that a car achieves is a function of the car's speed s (in miles per hour), given by F(s). Explain the meaning of F'(60) = -0.104 in the context of the car's fuel economy.