posted by kasey .
The amount of snow fall falling in a certian mountain range is normally distributed with a mean of 83 inches, and a standard deviation of 16 inches. What is the probability that the mean annual snowfall during 64 randomly picked years will exceed 85.8 inches?
Use this formula to find z:
z = (x - mean)/(sd/√n)
With your data:
z = (85.8 - 83)/(16/√64) = ?
Once you have the z-score, look at the z-table to determine your probability.
I hope this will help get you started.