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In the data set below, what is the variance?\newline8,8,7,5,9,4,88, 8, 7, 5, 9, 4, 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?\newline8,8,7,5,9,4,88, 8, 7, 5, 9, 4, 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 = (8+8+7+5+9+4+8)/7(8 + 8 + 7 + 5 + 9 + 4 + 8)/7\newlineμ=49/7\mu = 49/7\newlineμ=7\mu = 7
  2. Calculate Squared Differences: Data set: 8,8,7,5,9,4,88, 8, 7, 5, 9, 4, 8
    μ=7\mu = 7
    Calculate the sum of the squared differences from the mean.
    (87)2+(87)2+(77)2+(57)2+(97)2+(47)2+(87)2(8 - 7)^2 + (8 - 7)^2 + (7 - 7)^2 + (5 - 7)^2 + (9 - 7)^2 + (4 - 7)^2 + (8 - 7)^2
    =(1)2+(1)2+(0)2+(2)2+(2)2+(3)2+(1)2= (1)^2 + (1)^2 + (0)^2 + (-2)^2 + (2)^2 + (-3)^2 + (1)^2
    =1+1+0+4+4+9+1= 1 + 1 + 0 + 4 + 4 + 9 + 1
    =20= 20
  3. Calculate Variance: We know:\newlineΣ(xiμ)2=20\Sigma(x_i - \mu)^2= 20\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=207\sigma^2 = \frac{20}{7}\newlineσ22.857\sigma^2 \approx 2.857\newlineRound to the nearest tenth: σ22.9\sigma^2 \approx 2.9

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