Problem 3 AtoZ is an online shopping company. This firm has a sales support center (i.e., call center) that handles queries from customers through phone calls. The call center operates for 160 hours per month and every worker in this call center works full-time (160 hours per month). Assume that, at the end of December 2019, there are 10 permanent workers in the call center. A permanent worker receives a wage of $2000 per month. It takes each permanent worker on average 40 minutes to process a call. To ensure a high service level, all customer queries must be resolved by the end of the month (i.e., no carryover of questions or web chats from month to month). The monthly demand forecasts for 2020 are given as follows: Month Demand Forecast (Number of calls) Jan-20 Feb-20 Mar-20 Apr-20 May-20 Jun-20 Jul-20 Aug-20 Sep-20 Oct-20 Nov-20 Dec-20 3,240 3,960 3,480 2,604 4,008 2,880 2,436 4,140 2,940 3,732 4,236 3,564 For quality reasons, the company decides to use a level plan where the number of permanent workers is constant throughout 2020. The number of permanent workers needed is equal to the number of workers required to meet the average demand over the 12-month planning horizon. Additional permanent workers can be hired only once in the year, at beginning of January 2020. Similarly, any lay off decisions of permanent workers must also be made at the beginning of January 2020. As a result, permanent workers cannot be hired or laid off during the planning horizon (year) other than the beginning of January. It costs $400 to hire and train a new permanent worker, and $100 to lay off a permanent worker. The permanent workforce is supplemented with temporary workers in months where the demand is higher than the average demand. Management can hire temporary contract agents who work for one month at a cost of $1000/month. No hiring or layoff costs are incurred for the contract agents. The temporary workers work at the same rate as the permanent workers, and they do not require any training. For months where the demand is lower than the permanent workers' total productivity, please assume the following: any idle permanent staff is assigned to administrative jobs or training sessions, and hence a permanent worker continues to receive his/her full pay for that month. Please prepare a staffing plan from January 2020 to December 2020 and show the size of the permanent workforce and the number of temporary workers needed (if any) on a monthly basis. What is the total cost of this plan