Q7. (15 points) Suppose that a Zoom cell phone customer has a choice of four monthly leasing plans: Plan I: $20 per month and $.40 per minute Plan II: $30 per month with 20 free minutes and $.30 per minute for additional minutes Plan III: $40 per month with 30 free minutes and $.20 per minute for additional minutes Plan IV: $60 per month with 100 free minutes and $.10 per minute for additional minutes Suppose also that the customer estimates that the amount of time he/she will talk on the cell phone each month can be approximated by the following distribution: Time Probability 10 minutes .20 30 minutes .20 60 minutes 30 100 minutes 20 150 minutes 10 Required: Determine which plan the customer should choose if the objective is to minimize the expected monthly cost.