From the Following Grouped Data, Find the Sample Standard Deviation

Multiple Choice

From the following grouped data, find the sample standard deviation. $$\begin{array} { | l | l | l | l | } \hline \text { Interval } & \text { Midpoint } x & \text { Frequency } f & \text { Product } x f \\\hline 41.5 - 48.5 & & 10 & \\\hline 48.5 - 55.5 & & 16 & \\\hline 55.5 - 62.5 & & 18 & \\\hline 62.5 - 69.5 & & 25 & \\\hline 69.5 - 76.5 & & 4 & \\\hline 76.5 - 83.5 & & 1 & \\\hline\end{array}$$ Round your answer to the nearest whole number.

A) 5
B) 17
C) 8
D) 11
E) 7