Question 1184149
<pre>
If X is a random variable with mean &mu; and standard deviation &sigma;,
then the random variable Y = aX + b has mean = a&mu; + b, and 
standard deviation a&sigma;.

Therefore, since X is a random variable with mean 3 and standard deviation 2,
random variable Y = 2X + 7 has mean 2(3) + 7 = 13 and standard deviation 
2(2) = 4, so its variance is 4<sup>2</sup> = 16.

Edwin</pre>