Question

Emma wants to compare some cell phone plans by graphing their cost per text message. Mobilama charges a flat rate of $30 for unlimited texts. Celly-On-The-Go has no set-up charge, but it does charge $0.10 per text. Ringit Wireless only charges $0.05 per text, but it has an account charge of $15.
Explain to Emma how she can graph these cell phone plans and, describe what key features of the graphs she should consider when making a decision. @kirbykirby

Answer 1

Calculate the cost per text for each alternative for each text. For example, the cost per text at 10 text would be $ 3 ($ 30 / 10) for Mobliama, ,10 for Celly-On-The Go, and $ 1,55 (.05 + ($ 15/10 texts) for Ring-It Wireless. You will need to do the calculation for 20, 30, 40, 50, 60, 70, 80, 90 and 100 text.
2. Set up a graph the horizontal axis, the bottom, you need ten units of measure starting at zero with the first unit of measure being 10. The horizontal axis is the number of text. The vertical axis, the left line, would have 10 units of measure starting at .30 and ending with $ 3, The vertical axis is cost per text.
3. Now starting with Mobliama find the point on the graph where a line from the bottom at 10 meets a line from the left at $ 3. Put a dot there. Repeat this nine times using the computation you made in part 1 for each unit of measure. When you are finished connect each dot with a line. Repeat this process for Celly-On-The-Go and Ring-it-Wireless.

Answer 2

In the center at the top of the graph enter your label "Cost per Text"