Suppose there are 12 jobs to be processed and 4 identical machines available to process these jobs. The processing time of each individual job is shown below. If two or more jobs are assigned to a machine, the total processing time of this machine is equal to the sum of the processing times of all the jobs assigned to this machine. These jobs must be completed within 15 hours (i.e., the total processing time of each machine cannot exceed 15 hours).

Job	Processing Time (hours)
1	2.8
2	5.5
3	4.3
4	1.4
5	3.4
6	2.5
7	2.4
8	4.0
9	3.0
10	4.4
11	3.8
12	3.5

Consider the following two problems independently. Formulate each problem as an integer programming model and solve each problem using Excel Solver.

• Assuming to use all the machines, the problem is to assign these jobs to the machines so as to maximize the minimum total processing time of the machines (i.e., to balance the workload of each machine as evenly as possible).
• Any existing functions (e.g., Max(), Min(), etc.) in Excel cannot be used except Sum() and Sumproduct().