Original Mean: 40, Standard Deviation: 15
Two scores were misread: 25 → 52 and 35 → 53
Corrected Mean:
\( \mu' = \frac{3955}{100} = \boxed{39.55} \)
Corrected Standard Deviation:
\( \sigma' = \sqrt{\frac{178837}{100} - (39.55)^2} \approx \boxed{14.96} \)
✅ Final Answer: Mean = 39.55, Standard Deviation ≈ 14.96
| Class interval | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 | 70-80 |
| Frequency | 180 | $f_1$ | 34 | 180 | 136 | $f_2$ | 50 |
Given: Median = 42.6, Total Frequency = 685
Using Median Formula:
\( \text{Median} = L + \left( \frac{N/2 - F}{f} \right) \cdot h \)
Substituting values:
\( 42.6 = 40 + \left( \frac{128.5 - f_1}{180} \right) \cdot 10 \Rightarrow f_1 = \boxed{82} \)
Using total frequency:
\( 662 + f_2 = 685 \Rightarrow f_2 = \boxed{23} \)
✅ Final Answer: \( f_1 = 82,\quad f_2 = 23 \)
Online Test Series, Information About Examination,
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and More.
Online Test Series, Information About Examination,
Syllabus, Notification
and More.