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In the data set below, what is the variance?\newline1,9,9,9,7,4,31, 9, 9, 9, 7, 4, 3\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?\newline1,9,9,9,7,4,31, 9, 9, 9, 7, 4, 3\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 = (1+9+9+9+7+4+3)/7(1 + 9 + 9 + 9 + 7 + 4 + 3)/7\newlineμ=42/7\mu = 42/7\newlineμ=6\mu = 6
  2. Calculate Sum of Squared Differences: Data set: 1,9,9,9,7,4,31, 9, 9, 9, 7, 4, 3
    μ=6\mu = 6
    Calculate the sum of the squared differences from the mean.
    (16)2+(96)2+(96)2+(96)2+(76)2+(46)2+(36)2(1 - 6)^2 + (9 - 6)^2 + (9 - 6)^2 + (9 - 6)^2 + (7 - 6)^2 + (4 - 6)^2 + (3 - 6)^2
    =(5)2+(3)2+(3)2+(3)2+(1)2+(2)2+(3)2= (-5)^2 + (3)^2 + (3)^2 + (3)^2 + (1)^2 + (-2)^2 + (-3)^2
    =25+9+9+9+1+4+9= 25 + 9 + 9 + 9 + 1 + 4 + 9
    =66= 66
  3. Calculate Variance: We have:\newlineΣ(xiμ)2=66\Sigma(x_i - \mu)^2= 66\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=667\sigma^2 = \frac{66}{7}\newlineσ29.4\sigma^2 \approx 9.4 when rounded to the nearest tenth.

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