Questions: Find the sample variance and standard deviation.
18,12,5,8,11
Choose the correct answer below. Fill in the answer box to complete your choice.
(Type an integer or a decimal. Round to one decimal place as needed.)
A. σ²=
B. s²=
Transcript text: Find the sample variance and standard deviation.
\[
18,12,5,8,11
\]
Choose the correct answer below. Fill in the answer box to complete your choice.
(Type an integer or a decimal. Round to one decimal place as needed.)
A. $\sigma^{2}=$ $\square$
B. $s^{2}=$ $\square$
Solution
Solution Steps
Step 1: Determine if the calculation is for a population or a sample
The calculation is for a sample.
Step 2: Calculate the mean
The mean (\(\mu\) or \(\bar{x}\)) is calculated as \(\frac{1}{5}\sum_{i=1}^{5}x_i\), which equals 10.8.
Step 3: Calculate the variance
The sample variance (\(s^2\)) is calculated as \(\frac{1}{5-1}\sum_{i=1}^{5}(x_i - \bar{x})^2\), which equals 23.7.
Step 4: Calculate the standard deviation
The sample standard deviation (\(s\)) is the square root of \(s^2\), which equals 4.9.
Final Answer:
The sample variance is 23.7 and the sample standard deviation is 4.9.