The simplest cost function is the linear cost function, C(x) = mx + b, where the y-intercept b represents the fixed costs of operating a business and the slope m represents the cost of each item produced. Suppose that a small bicycle manufacturer has daily fixed costs of $1800 and each bicycle costs $90 to manufacture.

(a) Write a linear model that expresses the cost C of manufacturing x bicycles in a day.

(b) Graph the model.

(c) What is the cost of manufacturing 14 bicycles in a day?

(d) How many bicycles could be manufactured for $3780?