if the formula *photo* were used to find the r-value of the following data, what would be the value of sy to three decimal places?

We have to find the value of sx for the table given.
sx represents the sample standard deviation of x.
Then, we start by calculating the mean of x:
[tex]\begin{gathered} \bar{x}=\frac{1}{n}\sum x_i \\ \\ \bar{x}=\frac{1}{5}(2+5+7+11+15)=\frac{1}{5}(40)=8 \end{gathered}[/tex]We now can calculate the standard deviation as:
[tex]\begin{gathered} s^2=\frac{1}{n-1}\sum(x_i-\bar{x})^2 \\ s^2=\frac{1}{4}[(2-8)^2+(5-8)^2+(7-8)^2+(11-8)^2+(15-8)^2] \\ s^2=\frac{1}{4}[(-6)^2+(-3)^2+(-1)^2+3^2+7^2] \\ s^2=\frac{1}{4}[36+9+1+9+49] \\ s^2=\frac{1}{4}[104] \\ s^2=26 \\ s=\sqrt{26} \\ s\approx5.099 \end{gathered}[/tex]We have obtained the approximate value of sx as 5.099.
Answer: 5.099 [Option C]