In the year 2005, the postage for a first-class letterwas 37 cents for weights up to 1 oz and 23 cents more for each additional ounce or fraction of an ounce. A. Sketch the graph of this function.

B. Using a transformation of the greatest integer function, write an equation for the 2005 postage as a function of the weight.

C. In 2005, first-class postage rates applied only until the letter reached the weight at which the postage would exceed $3.13. What is the domain of the function in part b?