What Proportion of the Data from a Normal Distribution Is

Short Answer

What proportion of the data from a normal distribution is within 2 standard deviations of the mean? $\begin{array}{|l|l|}\hline\text { A. } & 0.3413 . \\\hline \text { B. } & 0.4772 . \\\hline \text { C. } & 0.6826 . \\\hline \text { D. } & 0.9544 . \\\hline\end{array}$