1. Phone is $60 Calls 30cents per min Phone is $80 Calls 10cents per min Straight Line Graphs Pay as you Go Cell Phones Step 1: Complete the four tables on sheet 2 for the following Pay as you Go Cell Phone deals: Step 2: Using the values in your tables, plot each of the Cell Phone deals on the graph on sheet 2, take care to ensure you plot the points and draw the lines accurately (use a different colored pencil for each line). Ensure your lines and axes are labeled correctly. Phone is $45 Calls 40cents per min Phone is $50 Calls 35cents per min Step 4: Explain below why it is important to identify the number of calls you are likely to make before selecting a Pay as you Go Cell phone deal. Use examples to illustrate your point. Name: 1 Step 3: Write down the equation of the line (in the form y = mx + c) for each of the Cell phone deals: O2:O2: Virgin: T-mobile: 3:

2. Straight Line Graphs Pay as you Go Mobile Phones Discuss the answers to the following questions in your team, then write down your own answers. 1. How many minutes of calls do you need to make for the 3 phone to be the cheapest deal? 3. Hiresh needs a phone for 6 months and he estimates that he will make between 90 and 130 minutes of calls in that time. What phone deal would you recommend he purchases and why? Provide examples of call costs in your answer. Name: 3 2. Jane estimates that she will make 7 minutes of calls per month over a year. b. How much will this cost her? c. If she chose an alternative provider, what is the most it could cost her? Who is this with? 4. Grandpa Bob wants to buy his first mobile phone, he has $200 in total to spend on the phone and calls over 2 years. What is the maximum number of calls he can make? Which provider is this with? Show your working. a. Based on your graph, what phone deal would you recommend she purchases? d. Calculate your answers to b and c using the relevant equations:

3. Z Calls (min) 050100200250 Cost ($) Calls (min) 050100200250 Cost ($) Calls (min) 050100200250 Cost ($) Calls (min) 050100200250 Cost ($) 2 100150500200250 0 50 100 150