No idea how to do this. I looked in my book and there usually is a data set present to get the first, second and third quartile.
The lifetimes of lightbulbs of a particular type are normally distributed with a mean of 392 hours and a standard deviation of 9 hours. Find the first quartile Q1.
You are given a normal distribution. If you mean the upper quartile by Q1, then the upper 25 percent has to be found by statistical methods. I suspect you are supposed to be using your calculator or a chart with the given mean and std deviation. I get 396 for that upper quartile.
http://psych.colorado.edu/~mcclella/java/normal/accurateNormal.html
WELL I KNOW YOU SUPPOSE TO BE DEALING WITH MATH BUT AIN'T YOU SUPPOSE TO ASK A QUESTION?