JEE Mains · Maths · STD 11 - 13. statistics
If the variance of the following frequency distribution is \(50\) then \(x\) is equal to:
| Class | \(10-20\) | \(20-30\) | \(30-40\) |
| Frequency | \(2\) | \(x\) | \(2\) |
- A \(4\)
- B \(-2\)
- C \(-4\)
- D \(2\)
Answer & Solution
Correct Answer
(A) \(4\)
Step-by-step Solution
Detailed explanation
Variance is independent of shifting of origin \(\Rightarrow y_{i}: 15 \quad 25 \quad 35 \;\; or\;\;-10 \quad 0 \quad 10\) \(\Rightarrow f_{i}: 2 \quad \;\;\;x \quad \;2 \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\; 2 \quad \;\;x \quad \;2\) \(\Rightarrow \quad\) Variance…
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