JEE Main 2024 Mathematics question

Let the mean and the variance of 6 observations a, b, 68, 44, 48, 60 be 55 and 194, respectively. If a > b, then a + 3b is

Answer: (A)

Solution

The mean is 55, so a + b + 220 = 330 and a + b = 110. The variance is 194: Σx²/6 − 55² = 194, so Σx² = 6 × 3219 = 19314. The known squares sum to 68²

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Question ID VK-017265