Given Independent Random Variables with Means and Standard Deviations as Shown,find

question 38

Multiple Choice

Given independent random variables with means and standard deviations as shown,find the mean and standard deviation of the variable 2X. $$\begin{array} { c | c c } & \text { Mean } & \text { SD } \\\hline \mathrm { X } & 40 & 5 \\\mathrm { Y } & 70 & 8\end{array}$$

• A)? = 80,? = 5
• B)? = 42,? = 5
• C)? = 42,? = 10
• D)? = 80,? = 10
• E)? = 80,? = 20