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JEE Mains · Maths · STD 11 - 13. statistics
If the mean of the data : \(7, 8, 9, 7, 8, 7, \mathop \lambda \limits^. , 8\) is \(8\), then the variance of this data is
- A \(\frac{9}{8}\)
- B \(2\)
- C \(\frac{7}{8}\)
- D \(1\)
Answer & Solution
Correct Answer
(D) \(1\)
Step-by-step Solution
Detailed explanation
\(\left( d \right)\,\,\bar x = \frac{{7 + 8 + 9 + 7 + 8 + 7 + \lambda + 8}}{8} = 8\) \( \Rightarrow \frac{{54 + \lambda }}{8} = 8 \Rightarrow \lambda = 10\) Now variance \( = {\sigma ^2}\)…
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