If X Is a Normal Random Variable with a Standard

Short Answer

If X is a normal random variable with a standard deviation of 10, then 3X has a standard deviation equal to: $\begin{array}{|l|l|}\hline\text { A. } & 10 . \\\hline \text { B. } & 13 . \\\hline \text { C. } & 30 . \\\hline \text { D. } & 90 . \\\hline\end{array}$