What formula should I use to calculate the 25th and 75th percentile on excel?

I attached the table that I made for this problem

The manufacturer of a particular bicycle model has the following costs associated with the management of this product's inventory. In particular, the company currently maintains an inventory of 1000 units of this bicycle model at the beginning of each year. If X units are demanded each year and X is less than 1000, the excess supply, 1000 - X units, must be stored until next year at a cost of $50 per unit. If X is greater than 1000 units, the excess demand, X 1000 units, must be produced separately at an extra cost of $80 per unit. Assume that the annual demand (X) for this bicycle model is normally distributed with mean 1000 and standard deviation 75. a. Find the expected annual cost associated with managing potential shortages or surpluses of this product. Round your answers to the nearest dollar, if necessary. (Hint: Use simulation to approximate the answer. Run the simulation 10,000 times. An exact solution using probability arguments is beyond the level of this book.) Storage 1631 Shortage 2323 Total 3868 b. Find two annual total cost levels, equidistant from the expected value found in part a, such that 95% of all costs associated with managing potential shortages or surpluses of this product are between these values. Round your answers to the nearest dollar, if necessary. (Continue to use simulation.) 2.5th percentile 97.5th percentile C. Comment on this manufacturer's annual production policy for this bicycle model in light of your findings in part b. The total cost Select but its mean Select B C D E F G 1 Trial 2 3 Simulation Result Storage Shortage Total 1529.496 2460.2806 3989.7765 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Demand Storage Shortage 1 986.58416 0 32.884217 2 1032.8842 15.265515 0 3 984.73449 138.6791 0 4 861.3209 209.85081 0 5 790.14919 0 102.7578 6 1102.7578 16.289036 0 7 983.71096 82.263109 8 1082.2631 65.917926 0 9 934.08207 0 114.8608 10 1114.8608 43.842015 0 11 956.15799 0 117.26516 12 1117.2652 0 83.871384 13 1083.8714 0 72.980749 14 1072.9807 124.12329 0 15 875.87671 0 89.049576 16 1089.0496 101.83015 0 17 898.16985 0 175.67177 18 1175.6718 64.757459 0 19 935.24254 53.542997 0 20 946.457 0 69.822226 21 1069.8222 0 24.928882 22 1024.9289 121.05963 0 23 878.94037 0 14.752892 24 1014.7529 119.76284 0 25 880.23716 45.320891 0 26 954.67911 119.23425 0 27 880.76575 0 78.647321 28 1078.6473 51.345888 0 29 948.65411 27.64736 0 30 972.35264 50.131434 0 31 949.86857 62.062173 32 1062.0622 0 22.825286 33 1022.8253 0 44.134701 34 1044.1347 29.206292 0 35 970.79371 80.376033 0 36 919.62397 0 19.48883 37 1019.4888 0 25.831108 38 1025.8311 0 3.5086072 39 1003.5086 0 27.792681 40 1027.7927 5.2058088 0 41 994.79419 0 40.418675 29 30 31 32 33 34 35 36 37 38 39 40 41 42 A