Question 4 (10 points): A landscaping company company needs 43, 73, 21, 78, and 99 tones of a specific type of soil during the next five months (backlogging is not allowed). In the next five months, the purchase price of this soil is estimated to be $5500, $8930, $1006, 5289, and $7000 per tones, respectively. The storage cost per tone are $400, $500, $550, $600, and $660 for the next five months (this cost is considered on inventory at the end of months). The company expects that, at the end of month 5, the remaining stock could be sold for $1600 per tone. Write a mathematical programming model to minimize the total cost ofthe company to cover the demands for the next five months