Assume Al, Beth, Carol, David, and Ed receive incomes of $125,000, $100,000, $80,000, $55,000, and $40,000 respectively.
What percentage of total income is received by the richest and by the poorest quintiles?
By the richest quintile: ______ %
By the poorest quintile:______%
The total income of the complete population is the sum of $125,000, $100,000, $80,000, $55,000, and $40,000. This is equal to $400,000. The percentage of total income received by the richest quintile is (125000/400000)*100 = 31.25%. The percentage of the total income received by the poorest quintile is (40000/400000)*100 = 10%
Each of these people is one-fifth of the entire population, therefore each person counts as one quintile with Al being the richest quintile and Ed being the poorest. To determine the percentage of total income that each of them receives, add up all the income numbers. Just eyeballing it quickly, it looks like $400,000 but you should check that. Then you take Al's income and divide it by the sum of everyone's income. (125/400 = 31.25%, but again, check the math) That gives you his percentage of the total income. Do the same for Ed.