Aptitude Topics
Marks Problems
Adjusting datasets when individual data entries are incorrectly transcribed or modified.
Fundamental Principles
Data Rectification Balance
Re-evaluating a dataset by swapping incorrect data points with correct ones to find the true mean.
Essential Formulation Tips
- Net Error = Correct Value - Incorrect Value. Add this error directly to the initial cumulative sum.
Shortcut Execution Techniques
- Correct Average = Original Average + (Net Error / Total Student Count).
Contextual Inquiries (FAQs)
Q: What happens if the recorded score is higher than the actual grade?
A: The net error is negative, which reduces the overall average score.
Example Breakdown: Correcting a Misread Score
Extremely frequent examination layout standard.Problem QueryThe average marks of 10 students were found to be 40. Later, it was discovered that a score of 50 was misread as 20. Find the correct average.
Step-By-Step Solution Path
Net Change = 50 (correct) - 20 (wrong) = +30.
Average adjustment = +30 / 10 students = +3.
True Corrected Average = 40 + 3 = 43.
Analytical Hint: Determine the net difference and share it equally among all items.
Exam Marks Correction Sets
Practice correcting misrecorded data.
Q1. Average marks of 5 items is 50. A score of 80 was misread as 30. What is the correct average?