The variance of x, 2x, 3x, 4x and 5x is

Explanation

Hint: prepare a three-columned table, one for (x), another for the (deviation), and the last for the (squared-deviation).

Sum of (x) = 15x, algebraic sum of (deviation) = zero (0)
Sum of (squared-deviation) = 10x²

Variance = ∑(squared-deviation)/n = 10x²/5 = 2x²

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