SOLVED:The given values represent data for a population. Find the variance and the standard deviation for each set of data. \begin{array}{|c|c|}\hline x_{i} & {f_{i}} \\ \hline 20 & {21} \\ {25} & {10} \\ {30} & {1} \\ {35} & {2} \\ {40} & {2} \\ {40} & {2} \\ {50} & {4} \\ {50} & {5} \\ {55} & {3} \\ {60} & {7} \\ \hline\end{array}