Year	Sales	Cost/exp
3	3.4225	3.0121
4	3.7575	3.4315
5	3.9332	3.6257
6	4.7512	3.8023
7	4.9768	4.5400
8	5.5485	4.8231
9	5.7225	5.0321
10	6.1668	5.8500
11	5.9600	5.9523
12	6.0927	5.6871
13	5.6223	6.3110
14	5.5012	6.6321
15	4.8853	7.7423

1)IN EXCEL model Sales Revenue R(x) as a quadratic function

2) use the quadratic function in 1 determine year of maximum revenue

3) In EXCEL model the cost/expenses as a quadratic function

4) using the data set in table, model Profit Function as a quadratic, where is the maximum profit

5) from 2008-15 P(x) is decreasing, does it support real data? Why?