An inequality is a mathematical expression that shows the relationship between two values that are not equal. Inequalities are typically represented using symbols such as < (less than), > (greater than), ≤ (less than or equal to), or ≥ (greater than or equal to).
To calculate an inequality, you need to follow the same rules as solving an equation, but with one key difference: when you multiply or divide by a negative number, you must reverse the direction of the inequality symbol.
For example, let's solve the inequality 2x + 5 > 11:
1. Subtract 5 from both sides: 2x > 6 2. Divide by 2: x > 3
So the solution to the inequality 2x + 5 > 11 is x > 3. This means that any value of x greater than 3 will satisfy the inequality.
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Google Gemini AI
2 days ago
Gini Coefficient
The Gini coefficient measures the income inequality of a population by calculating the area between the Lorenz curve and the perfect equality line.
Formula:
``` Gini coefficient = 2 - (n-1) / n - Σ(j=1 to n-1) j-(x[j+1] - x[j]) / Σ(j=1 to n) x[j] ```
- n: number of individuals in the population - x[j]: income of individual j, sorted in ascending order
Interpretation:
- 0: perfect equality - 1: perfect inequality
Lorenz Curve
The Lorenz curve is a graphical representation of income inequality. It shows the cumulative percentage of income received by each percentile of the population.
Formula:
``` Cumulative percentage of income = Σ(j=1 to i) x[j] / Σ(j=1 to n) x[j] ```
- i: percentile
Interpretation:
- A perfectly equal society would have a diagonal Lorenz curve, indicating that each percentile receives the same percentage of income. - A perfectly unequal society would have a Lorenz curve hugging the bottom axis, indicating that the top percentile receives all the income.
Other Inequality Measures
- Mean Absolute Deviation (MAD): Measures the average deviation of individual incomes from the mean income. - Theil Index: Measures income inequality based on the entropy of the income distribution. - Hoover Index: Measures income inequality by dividing the sum of income gaps by the total income. - Dalton Index: Measures income inequality by calculating the ratio of the mean income of the poorest half of the population to the mean income of the richest half of the population.
Considerations:
- These measures only consider income inequality and do not account for other forms of inequality (e.g., wealth, education, health). - The choice of inequality measure depends on the specific research question and the data available.