Problem: Sales of hot dogs at the corner of Polk and Castro follow the following pattern: 30% of the days, 80 are sold; 40% of the days, 90 are sold; and the remaining days, 100 are sold. If 90 are stocked each day by the vendor, what demand fill rate is the vendor targeting? How much should be stocked to have a fill rate of 98%? Please show your work for both step by step.