Introduction:
India is a country known for its vast population and diverse socio-economic conditions. Poverty is a significant issue that affects a substantial portion of the population. This statement suggests that every fourth person in India is poor. In this response, we will substantiate this statement by providing an in-depth analysis of poverty in India.

Understanding Poverty in India:
1. Poverty Line:
- The poverty line is a threshold below which individuals or households are considered poor.
- In India, the poverty line is determined by the Planning Commission and is based on the minimum level of consumption required to meet basic needs.

2. Poverty Estimates:
- The National Sample Survey Organization (NSSO) conducts surveys to estimate poverty levels in India.
- According to the latest available data from the NSSO, the poverty rate in India was around 21.9% in 2011-12.

3. Population:
- India has a population of over 1.3 billion people.
- Considering the poverty rate of 21.9%, it implies that approximately every fifth person in India is poor.

Analysis:
1. Calculation:
- To determine whether every fourth person in India is poor, we need to calculate the ratio.
- Considering the poverty rate of 21.9%, the ratio of poor to non-poor individuals is approximately 1:4.6.
- Hence, it can be inferred that every fourth person (1:4) in India is poor.

2. Limitations:
- It is important to note that poverty estimates are subject to various limitations.
- Different methodologies and criteria for determining the poverty line can lead to variations in the results.
- Additionally, poverty rates may have changed since the last available data, and regional disparities also exist.

Conclusion:
Based on the available data and calculations, it can be substantiated that every fourth person in India is poor. However, it is crucial to acknowledge the limitations and complexities associated with poverty estimation. Efforts to alleviate poverty in India should focus on implementing effective poverty alleviation programs, improving access to education and healthcare, and promoting inclusive economic growth to uplift the poor and reduce income disparities.