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In the data set below, what is the variance?\newline4,4,4,9,7,3,44, 4, 4, 9, 7, 3, 4\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?\newline4,4,4,9,7,3,44, 4, 4, 9, 7, 3, 4\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+4+4+9+7+3+4)/7(4 + 4 + 4 + 9 + 7 + 3 + 4)/7\newlineμ=35/7\mu = 35/7\newlineμ=5\mu = 5
  2. Calculate Sum of Squared Differences: Data set: 4,4,4,9,7,3,44, 4, 4, 9, 7, 3, 4
    μ=5\mu = 5
    Calculate the sum of the squared differences from the mean, Σ(xiμ)2\Sigma(x_i - \mu)^2.
    (45)2+(45)2+(45)2+(95)2+(75)2+(35)2+(45)2(4 - 5)^2 + (4 - 5)^2 + (4 - 5)^2 + (9 - 5)^2 + (7 - 5)^2 + (3 - 5)^2 + (4 - 5)^2
    =(1)2+(1)2+(1)2+(4)2+(2)2+(2)2+(1)2= (-1)^2 + (-1)^2 + (-1)^2 + (4)^2 + (2)^2 + (-2)^2 + (-1)^2
    =1+1+1+16+4+4+1= 1 + 1 + 1 + 16 + 4 + 4 + 1
    =28= 28
  3. Calculate Variance: We know:\newlineΣ(xiμ)2=28\Sigma(x_i - \mu)^2= 28\newlineN=7N= 7\newlineCalculate the variance and round your answer to the nearest tenth.\newlineσ2=(Σ(xiμ)2)/N\sigma^2 = (\Sigma(x_i - \mu)^2)/N\newlineσ2=28/7\sigma^2 = 28/7\newlineσ2=4\sigma^2 = 4\newlineSince the result is not a decimal, there is no need to round.

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