Fate of Individual Observations After Classification
What happens to individual observations after data is grouped into classes in a frequency distribution?
- They are used directly in all statistical calculations
- They are permanently deleted from the data
- They have no significance in further statistical calculations — class mark is used instead — Correct Answer
- They are rearranged in ascending order
Explanation:
Correct Answer Explanation
Once data is grouped into classes, individual observations have no significance in further statistical calculations. Instead, the class mark is used.
Key Points:
- All values in a class are assumed equal to the class mark (mid-point).
- Example: Class 20–30 (class mark = 25) contains 6 values: 25, 25, 20, 22, 25, 28. All treated as 25 in calculations.
- This is the 'Loss of Information' — the price paid for making data manageable.
- The gain: data becomes concise, comprehensible and easy to analyse.
📚 About this Topic — CH-3: Organisation of Data
This multiple choice question is from CH-3: Organisation of Data, NCERT Books, Statistics for Economics. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from CH-3: Organisation of Data to strengthen your preparation.
