Proportions and Graphs

Solve the following problems. Record your solution strategy and then answer the questions that follow the problem set.

Problem 1: Exhausted Examiners: Elke and Faye corrected final exams at the same rate but Elke got a head start. When Elke had completed 12 exams Faye had finished only 4. When Elke had finished 60 exams, how many exams had Faye completed?

Problem 2: A Metric Conversion: If 6 inches is 15.24 cm, 9 inches is how many centimeters?

Problem 3: A Candy company is developing packaging for their Chocolates. If they place 60 candies in a long box, there can be 6 rows of 10 candies. If the company decides to use a different box with 4 rows, how many candies would there be in each of 4 rows?

Problem 4: Taken for a Ride: A taxicab charged $1 plus 50 cents a mile. If it costs $3 to go four miles, how much would it cost to go 6 miles?

Questions
A. Of Problems 1-4, which are proportion problems and which are not? Briefly justify your answers.

B. How do graphs of proportions differ from other graphs?

C. How can tables be used to identify proportions?

(Source: Adapted from Fostering Children’s Mathematical Power. An Investigative Approach to K-12 Mathematics, Arthur J. Baroody, with Ronald T. Coslick, c. 1998 by Lawrence Erlbaum Associates, Mahwah, NJ.)