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In the data set below, what is the variance?\newline4,7,9,4,3,7,84, 7, 9, 4, 3, 7, 8\newlineIf the answer is a decimal, round it to the nearest tenth.\newlinevariance (σ2)(\sigma^2): _____

Full solution

Q. In the data set below, what is the variance?\newline4,7,9,4,3,7,84, 7, 9, 4, 3, 7, 8\newlineIf the answer is a decimal, round it to the nearest tenth.\newlinevariance (σ2)(\sigma^2): _____
  1. Calculate Mean: Calculate the mean of the data set.\newlineMean = (4+7+9+4+3+7+8)/7(4 + 7 + 9 + 4 + 3 + 7 + 8)/7\newlineμ=42/7\mu = 42/7\newlineμ=6\mu = 6
  2. Calculate Sum of Squared Differences: Data set: 4,7,9,4,3,7,84, 7, 9, 4, 3, 7, 8
    μ=6\mu = 6
    Calculate the sum of the squared differences from the mean, Σ(xiμ)2\Sigma(x_i - \mu)^2.
    (46)2+(76)2+(96)2+(46)2+(36)2+(76)2+(86)2(4 - 6)^2 + (7 - 6)^2 + (9 - 6)^2 + (4 - 6)^2 + (3 - 6)^2 + (7 - 6)^2 + (8 - 6)^2
    =(2)2+(1)2+(3)2+(2)2+(3)2+(1)2+(2)2= (-2)^2 + (1)^2 + (3)^2 + (-2)^2 + (-3)^2 + (1)^2 + (2)^2
    =4+1+9+4+9+1+4= 4 + 1 + 9 + 4 + 9 + 1 + 4
    =32= 32
  3. Calculate Variance: We know:\newlineΣ(xiμ)2=32\Sigma(x_i - \mu)^2= 32\newlineN=7N= 7\newlineCalculate the variance and round your answer to the nearest tenth.\newlineσ2=Σ(xiμ)2N\sigma^2 = \frac{\Sigma(x_i - \mu)^2}{N}\newlineσ2=327\sigma^2 = \frac{32}{7}\newlineσ24.57142857\sigma^2 \approx 4.57142857\newlineRounded to the nearest tenth: σ24.6\sigma^2 \approx 4.6

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