Questions: Look at the following data and complete the table to find the sample standard deviation
17,8,12,26,17,29,10
Transcript text: Look at the following data and complete the table to find the sample standard deviation
\[
17,8,12,26,17,29,10
\]
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Solution
Solution Steps
To find the sample standard deviation, we need to follow these steps:
Calculate the mean (average) of the data set.
Subtract the mean from each data point and square the result.
Sum all the squared results.
Divide this sum by the number of data points minus one (n-1) to get the variance.
Take the square root of the variance to get the sample standard deviation.
Step 1: Calculate the Mean
The mean (\(\mu\)) of the data set is calculated as follows:
\[
\mu = \frac{\sum_{i=1}^{n} x_i}{n} = \frac{17 + 8 + 12 + 26 + 17 + 29 + 10}{7} = 17.0
\]
Step 2: Calculate Squared Differences
Subtract the mean from each data point and square the result:
\[
\begin{align_}
(17 - 17.0)^2 &= 0.0 \\
(8 - 17.0)^2 &= 81.0 \\
(12 - 17.0)^2 &= 25.0 \\
(26 - 17.0)^2 &= 81.0 \\
(17 - 17.0)^2 &= 0.0 \\
(29 - 17.0)^2 &= 144.0 \\
(10 - 17.0)^2 &= 49.0 \\
\end{align_}
\]
Step 3: Sum of Squared Differences
Sum all the squared differences:
\[
\sum (x_i - \mu)^2 = 0.0 + 81.0 + 25.0 + 81.0 + 0.0 + 144.0 + 49.0 = 380.0
\]
Step 4: Calculate the Variance
Divide the sum of squared differences by \(n-1\) (where \(n\) is the number of data points):
\[
\sigma^2 = \frac{\sum (x_i - \mu)^2}{n-1} = \frac{380.0}{7-1} = 63.3333
\]
Step 5: Calculate the Sample Standard Deviation
Take the square root of the variance to get the sample standard deviation:
\[
\sigma = \sqrt{\sigma^2} = \sqrt{63.3333} \approx 7.958
\]