SOLUTION
Step1; Write out the set of data
7, 13, 8, 3, 11, 7, 14, 7, 18, 2
The mean is given as


The mean is 9.00
The variance of a set of data is given as

consider the table below
![\begin{gathered} (\sigma^2=(2-9)^2+(3-9)^2+(7-9)^2+(7-9)^2+(7-9)^2+(8-9)^2+(11-9)^2+(13-9)+(14-9)^2+(18-9)^2)/(10) \\ \end{gathered}]()
Hence the variance becomes


The variance is 22.40
The standard deviation is given as
![\begin{gathered} \text{std}=\sqrt[]{variance} \\ \sigma=\sqrt[]{22.40}=4.73 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/621evz2gc1b995hdwqtzpz4jergjbu6am7.png)