stion 21 Class Interval Real Limits Cumulative f Cumulative % 93-99 94.5-99 5 100.00 90 - 94 89.5 - 94.5 94.29 85 - 89 84.3 - 89.5 85.71 80 - 84 79.5-84.5 75.71 73 - 79 74.5 - 79.5 61.43 70 - 74 69.5-74.5 38.37 65 - 69 64.5 - 69.5 25.71 60 - 64 39.5 - 64.3 15.71 55 - 59 54.5 - 39.5 10.00 50 - 54 49.5 - 54.5 4.29 45-49 44.5 - 49.5 1.43 Referring to the above frequency distribution and without calculation, a reasonable value for P40 would be 1.74.81 2.40.00 3.92.75 4.72.13