The mean of 100 observations was calculated as 40. It was found that an observation 53 was misread as 83. Find the correct mean.
Step-by-Step Solution
Key Concept: Incorrect sum $= 4000$. Correct sum $= 4000 - 83 + 53 = 3970$. Correct Mean $= 3970 / 100 = 39.7$.
Correct sum $= 4000 - 83 + 53 = 3970$. [1.0 Mark]
Correct mean $= 3970 / 100 = 39.7$. [1.0 Mark]
---
🎯 Official CBSE Marking Scheme:
Calculating correct sum $= 3970$: 1.0 Mark
Evaluating correct mean $= 39.7$: 1.0 Mark
Correct Answer: