Find the Variance 22 , 15 , 69 , 65 , 85 , 74 , 45 , 45 , 45 , 22

$22$ , $15$ , $69$ , $65$ , $85$ , $74$ , $45$ , $45$ , $45$ , $22$

Step 1

The mean of a set of numbers is the sum divided by the number of terms.

$\overline{x} = \frac{22 + 15 + 69 + 65 + 85 + 74 + 45 + 45 + 45 + 22}{10}$

Step 2

Simplify the numerator.

Add $22$ and $15$ .

$\overline{x} = \frac{37 + 69 + 65 + 85 + 74 + 45 + 45 + 45 + 22}{10}$

Add $37$ and $69$ .

$\overline{x} = \frac{106 + 65 + 85 + 74 + 45 + 45 + 45 + 22}{10}$

Add $106$ and $65$ .

$\overline{x} = \frac{171 + 85 + 74 + 45 + 45 + 45 + 22}{10}$

Add $171$ and $85$ .

$\overline{x} = \frac{256 + 74 + 45 + 45 + 45 + 22}{10}$

Add $256$ and $74$ .

$\overline{x} = \frac{330 + 45 + 45 + 45 + 22}{10}$

Add $330$ and $45$ .

$\overline{x} = \frac{375 + 45 + 45 + 22}{10}$

Add $375$ and $45$ .

$\overline{x} = \frac{420 + 45 + 22}{10}$

Add $420$ and $45$ .

$\overline{x} = \frac{465 + 22}{10}$

Add $465$ and $22$ .

$\overline{x} = \frac{487}{10}$

Step 3

Divide.

$\overline{x} = 48.7$

Step 4

Set up the formula for variance. The variance of a set of values is a measure of the spread of its values.

$s^{2} = \sum_{i = 1}^{n} \frac{{(x_{i} - x_{a v g})}^{2}}{n - 1}$

Step 5

Set up the formula for variance for this set of numbers.

$s = \frac{{(22 - 48.7)}^{2} + {(15 - 48.7)}^{2} + {(69 - 48.7)}^{2} + {(65 - 48.7)}^{2} + {(85 - 48.7)}^{2} + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Step 6

Simplify the result.

Simplify the numerator.

Subtract $48.7$ from $22$ .

$s = \frac{{(- 26.7)}^{2} + {(15 - 48.7)}^{2} + {(69 - 48.7)}^{2} + {(65 - 48.7)}^{2} + {(85 - 48.7)}^{2} + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Raise $- 26.7$ to the power of $2$ .

$s = \frac{712.89 + {(15 - 48.7)}^{2} + {(69 - 48.7)}^{2} + {(65 - 48.7)}^{2} + {(85 - 48.7)}^{2} + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Subtract $48.7$ from $15$ .

$s = \frac{712.89 + {(- 33.7)}^{2} + {(69 - 48.7)}^{2} + {(65 - 48.7)}^{2} + {(85 - 48.7)}^{2} + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Raise $- 33.7$ to the power of $2$ .

$s = \frac{712.89 + 1135.69 + {(69 - 48.7)}^{2} + {(65 - 48.7)}^{2} + {(85 - 48.7)}^{2} + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Subtract $48.7$ from $69$ .

$s = \frac{712.89 + 1135.69 + {20.3}^{2} + {(65 - 48.7)}^{2} + {(85 - 48.7)}^{2} + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Raise $20.3$ to the power of $2$ .

$s = \frac{712.89 + 1135.69 + 412.09 + {(65 - 48.7)}^{2} + {(85 - 48.7)}^{2} + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Subtract $48.7$ from $65$ .

$s = \frac{712.89 + 1135.69 + 412.09 + {16.3}^{2} + {(85 - 48.7)}^{2} + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Raise $16.3$ to the power of $2$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + {(85 - 48.7)}^{2} + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Subtract $48.7$ from $85$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + {36.3}^{2} + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Raise $36.3$ to the power of $2$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + {(74 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Subtract $48.7$ from $74$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + {25.3}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Raise $25.3$ to the power of $2$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + 640.09 + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Subtract $48.7$ from $45$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + 640.09 + {(- 3.7)}^{2} + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Raise $- 3.7$ to the power of $2$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + 640.09 + 13.69 + {(45 - 48.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Subtract $48.7$ from $45$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + 640.09 + 13.69 + {(- 3.7)}^{2} + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Raise $- 3.7$ to the power of $2$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + 640.09 + 13.69 + 13.69 + {(45 - 48.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Subtract $48.7$ from $45$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + 640.09 + 13.69 + 13.69 + {(- 3.7)}^{2} + {(22 - 48.7)}^{2}}{10 - 1}$

Raise $- 3.7$ to the power of $2$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + 640.09 + 13.69 + 13.69 + 13.69 + {(22 - 48.7)}^{2}}{10 - 1}$

Subtract $48.7$ from $22$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + 640.09 + 13.69 + 13.69 + 13.69 + {(- 26.7)}^{2}}{10 - 1}$

Raise $- 26.7$ to the power of $2$ .

$s = \frac{712.89 + 1135.69 + 412.09 + 265.69 + 1317.69 + 640.09 + 13.69 + 13.69 + 13.69 + 712.89}{10 - 1}$

Add $712.89$ and $1135.69$ .

$s = \frac{1848.58 + 412.09 + 265.69 + 1317.69 + 640.09 + 13.69 + 13.69 + 13.69 + 712.89}{10 - 1}$

Add $1848.58$ and $412.09$ .

$s = \frac{2260.67 + 265.69 + 1317.69 + 640.09 + 13.69 + 13.69 + 13.69 + 712.89}{10 - 1}$

Add $2260.67$ and $265.69$ .

$s = \frac{2526.36 + 1317.69 + 640.09 + 13.69 + 13.69 + 13.69 + 712.89}{10 - 1}$

Add $2526.36$ and $1317.69$ .

$s = \frac{3844.05 + 640.09 + 13.69 + 13.69 + 13.69 + 712.89}{10 - 1}$

Add $3844.05$ and $640.09$ .

$s = \frac{4484.14 + 13.69 + 13.69 + 13.69 + 712.89}{10 - 1}$

Add $4484.14$ and $13.69$ .

$s = \frac{4497.83 + 13.69 + 13.69 + 712.89}{10 - 1}$

Add $4497.83$ and $13.69$ .

$s = \frac{4511.52 + 13.69 + 712.89}{10 - 1}$

Add $4511.52$ and $13.69$ .

$s = \frac{4525.21 + 712.89}{10 - 1}$

Add $4525.21$ and $712.89$ .

$s = \frac{5238.1}{10 - 1}$

Simplify the expression.

Subtract $1$ from $10$ .

$s = \frac{5238.1}{9}$

Divide $5238.1$ by $9$ .

$s = 582.0\overline{1}$

Step 7

Approximate the result.

$s^{2} \approx 582.0111$

Find the Variance 22 , 15 , 69 , 65 , 85 , 74 , 45 , 45 , 45 , 22

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