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In the data set below, what is the variance?\newline1,9,4,7,81, 9, 4, 7, 8\newlineIf the answer is a decimal, round it to the nearest tenth.\newlinevariance (σ2)(\sigma^2): _____

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Q. In the data set below, what is the variance?\newline1,9,4,7,81, 9, 4, 7, 8\newlineIf the answer is a decimal, round it to the nearest tenth.\newlinevariance (σ2)(\sigma^2): _____
  1. Calculate Variance: Now, let's do the variance thing.\newlineWe need to sum up (each numbermean)2(\text{each number} - \text{mean})^2.\newlineSo, (15.8)2+(95.8)2+(45.8)2+(75.8)2+(85.8)2(1 - 5.8)^2 + (9 - 5.8)^2 + (4 - 5.8)^2 + (7 - 5.8)^2 + (8 - 5.8)^2\newlineThat's (4.8)2+(3.2)2+(1.8)2+(1.2)2+(2.2)2(4.8)^2 + (3.2)^2 + (1.8)^2 + (1.2)^2 + (2.2)^2\newlineWhich is 23.04+10.24+3.24+1.44+4.8423.04 + 10.24 + 3.24 + 1.44 + 4.84\newlineAdd 'em up, and we get 42.842.8
  2. Sum of Squares: Last step, divide that sum by the number of data points, which is 55.\newlineVariance (σ2\sigma^2) = 42.85\frac{42.8}{5}\newlineVariance (σ2\sigma^2) = 8.568.56\newlineRound it to the nearest tenth, and we get 8.68.6

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