Find the Standard Deviation for the Given Sample Data $$\begin{array} { l l l l l l l } 40 & 20 & 31 & 21 & 12 & 55 & 75\end{array}$$

Multiple Choice

Find the standard deviation for the given sample data. Round your answer to one more decimal place than is present in the original data.
-Christine is currently taking college astronomy. The instructor often gives quizzes. On the past seven quizzes, Christine got the following scores: $$\begin{array} { l l l l l l l } 40 & 20 & 31 & 21 & 12 & 55 & 75\end{array}$$

A) 12,196
B) 9216.6
C) 22.3
D) 31