Problem 5-6 I -2-2 I httpszezton't'ledu A. real estate agent is considering changing her cell phone plan. There are three plans to choose 'om, all of which involve a monthly service charge of $20. Plan it has a cost of $.40 a minute for daytime calls and $.20 a minute for evening calls. Plan B has a charge of $.50 a minute for daytime calls and $.14 a minute for evening calls. Plan C has a at rate of $75 with 200 minutes of calls allowed per month and a charge of $.33 per minute beyond that, day or evening. a. Determine the total charge under each plan for this case: 130 minutes of day calls and 50 minutes of evening calls in a month. (Do not round intermediate calculations. Round your answer to 2 decimal places. Omit the "5" sign in your response.) Cost for Plan A I Cost for Plan B I Cost for Plan C I c. If the agent will use the service for daytime calls, over what range of call minutes will each plan be optimal? (Round each answer to the nearest whole numberlnclude the indifference point itself in each answer.) Planllis optimal from zero to minutes. Plan C is optimal from minutes onward. l d. Suppose that the agent expects both daytime and evening calls. At what point (i.e., percentage of total call minutes used for daytime calls) would she be indifferent between plans A. and B? (Do not round intermediate