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If the mean of 50 observations is 25 and their standard deviation is 4 and the sum of the squares of all the observations is λ , then λ 1000 is

Correct answer

32.05

Step-by-step solution

Variance = ∑ i = 1 50 x i 2 n - x - 2 ⇒ 16 = ∑ i = 1 50 x i 2 50 - 25 2 ⇒ ∑ i = 1 50 x i 2 = 641 × 50 ∴ ∑ i = 1 50 x i 2 = 32050 = λ

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