In the data set below, what is the variance? 8, 8, 2, 9, 5, 2, 1 If the answer is a decimal, round it to the nearest tenth. variance (σ^2): _____

Calculate Variance: Now, let's do the variance thing. We need to sum up (each number - mean)^2. So, (8 - 5)^2 + (8 - 5)^2 + (2 - 5)^2 + (9 - 5)^2 + (5 - 5)^2 + (2 - 5)^2 + (1 - 5)^2 That's 3^2 + 3^2 + (-3)^2 + 4^2 + 0^2 + (-3)^2 + (-4)^2 Which is 9 + 9 + 9 + 16 + 0 + 9 + 16Sum of Squares: Add 'em all up for the sum. Sum = 9 + 9 + 9 + 16 + 0 + 9 + 16 Sum = 68Calculate Sum: Finally, divide by the number of data points to get variance. Variance = Sum / 7 Variance = 68 / 7 Variance = 9.71428571... Round it to the nearest tenth. Variance ≈ 9.7

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In the data set below, what is the variance? $\newline$ $8, 8, 2, 9, 5, 2, 1$ $\newline$ If the answer is a decimal, round it to the nearest tenth. $\newline$ variance $(\sigma^2)$ : _____

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Algebra 1

Variance and standard deviation

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Q. In the data set below, what is the variance?

\newline

8, 8, 2, 9, 5, 2, 1

\newline

If the answer is a decimal, round it to the nearest tenth.

\newline

variance

(\sigma^2)

: _____

Calculate Variance: Now, let's do the variance thing. $\newline$ We need to sum up $(\text{each number} - \text{mean})^2$ . $\newline$ So, $(8 - 5)^2 + (8 - 5)^2 + (2 - 5)^2 + (9 - 5)^2 + (5 - 5)^2 + (2 - 5)^2 + (1 - 5)^2$ $\newline$ That's $3^2 + 3^2 + (-3)^2 + 4^2 + 0^2 + (-3)^2 + (-4)^2$ $\newline$ Which is $9 + 9 + 9 + 16 + 0 + 9 + 16$
Sum of Squares: Add 'em all up for the sum. $\newline$ Sum = $9 + 9 + 9 + 16 + 0 + 9 + 16$ $\newline$ Sum = $68$
Calculate Sum: Finally, divide by the number of data points to get variance. $\newline$ Variance = $\frac{\text{Sum}}{7}$ $\newline$ Variance = $\frac{68}{7}$ $\newline$ Variance = $9.71428571\ldots$ $\newline$ Round it to the nearest tenth. $\newline$ Variance $\approx 9.7$