Jericho Agricultural Supply is mixing a fertilizer to sell to farmers. The agricultural supplier creates two fertilizer blends out of pure ingredients. Blend A uses 10 lbs of nitrogen, 10 lbs of phosphate, and 5 lbs of a proprietary ingredient in each 25 lb bag. Blend B uses 20 lbs of phosphate, 4 lbs of nitrogen, and 1 lb of the proprietary ingredient in each 25 lb bag. A bag of Blend A sells for $16, while a bag of Blend B sells for $18. The supplier has 200 lbs of phosphate, 240 lbs of nitrogen and 73 lbs of its proprietary ingredient to work with. They also know that they sell at least twice as many bags of Blend A as they do of Blend B. How many bags of each kind of fertilizer should the agricultural supplier mix to generate the maximum gross income? What if the amount of nitrogen available is only 160 lbs? Formulate a linear programming model and solve it graphically. Display your graph and calculate the maximum gross income. Create your graph using Microsoft Word or Excel.