Question 305673: Another measure of variation is variance, which equals mc005-1.jpg. Find the variance and standard deviation of the data set. Round to the nearest tenth.
3, 9, 11, 8, 7, 3
a) variance = 8.8;
standard deviation = 3
b) variance = 8.8;
standard deviation = 3.3
c) variance = 1.7;
standard deviation = 3.3
d) variance = 1.7;
standard deviation = 3
Really confused on how to find this answer. Thanks for anyone who explains!
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Another measure of variation is variance, which equals mc005-1.jpg. Find the variance and standard deviation of the data set. Round to the nearest tenth.
3, 9, 11, 8, 7, 3
a) variance = 8.8;
standard deviation = 3
b) variance = 8.8;
standard deviation = 3.3
c) variance = 1.7;
standard deviation = 3.3
d) variance = 1.7;
standard deviation = 3
Really confused on how to find this answer. Thanks for anyone who explains!
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To find the standard deviation you would have to:
1. find the mean of the data
2. find the different between each data value of the mean
3. square those differences
4. Add those squared values
5. divide the the number of data elements
That is the variance.
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6. find the square root of the result of step 5
That is the standard deviation.
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Note: You can find worked examples of this process online.
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The answer I get using a calculator is:
sigma = 2.97
variance = 8.8
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Cheers,
Stan H.
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