I'm new here and was hoping you guys could help me with a statistics problem that I don't quite understand. I'm not sure if it's proper etiquette to ask for help on a specific homework problem here, so I apologize if this question is out of line.
Here is the problem:
Suppose a variable of a population has mean 5 and standard deviation 11. For samples of size 121, find $c$ so that $P(X > 2c) = 0.3300$.