Posted by irene on Tuesday, September 17, 2013 at 9:26pm.
The international bottled water association says that Americans on the average drink 4.6 (8oz) servings of water a day. Assume that the number of 8oz. servings of water is approximately normally distributed with a standard deviation of 1.8 servings what proportion of Americans drink more than the recommended 8 servings?

statistics  PsyDAG, Wednesday, September 18, 2013 at 2:26pm
Z = (scoremean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.