WBJEE · Maths · Statistics
The variance of first 20 natural numbers is
- A \(133 / 4\)
- B \(279 / 12\)
- C 133/2
- D 399/4
Answer & Solution
Correct Answer
(A) \(133 / 4\)
Step-by-step Solution
Detailed explanation
Variance of \(n\) natural numbers \(=\frac{n^{2}-1}{12}=\frac{(20)^{2}-1}{12} \quad\) \([\because n=20]\), \(=\frac{400-1}{12}=\frac{399}{12}=\frac{133}{4}\)
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