4. The Kalo Fertilizer Company makes a fertilizer using two chemicals that provl e nitrogen, pnos- phate, and potassium. A pound of ingredient I contributes 10 ounces of nitrogen and 6 ounces of phosphate, whereas a pound of ingredic:n;. 2 contribtes 2 ounces of nitrogen, 6 ounces of phosphate, and I ounce of potassium. Ingredient costs $3 per pound, and ingredient 2 costs $5 per pound. The company wants to know how many pounds of each chemical ingredient to put into a bag of fertilizer to meet the minimum requirements of 20 ounces of nitrogen, 36 ounces of phosphate, and 2 ounces of potassium while minimizing cost. a. Formulate a linear programming model for this problem. b. Solve this model by using graphical analysis.