Total number of persons under study = Total number of persons in the age group of 15 years to 45 years, Number of persons from (15 – 20) + (20 – 25) + (25 – 30) + (30 – 35) + (35 – 40) + (40 - 45) = 450 + 250 + 150 + 100 + 75 + 50 = 1075 Maximum population in an age group 20 - 25 = 250 Ratio of maximum population in an age group 20 - 25 to the total number of persons under study = 250 : 1075 = 10 : 43