Rainfall Statistics from Cornell’s Northeast Regional Climate Center indicate that Ithaca, New York, gets an average of 35.4  of rain each year, with a standard deviation of 4.2 . Assume that a Normal...

Rainfall Statistics from Cornell’s Northeast Regional Climate Center indicate that Ithaca, New York, gets an average of 35.4  of rain each year, with a standard deviation of 4.2 . Assume that a Normal model applies.

 a) During what percentage of years does Ithaca get more than 40  of rain?

 b) Less than how much rain falls in the driest 20% of all years?

 c) A Cornell University student is in Ithaca for 4 years. Let y represent the mean amount of rain for those 4 years. Describe the sampling distribution model of this sample mean, y.

 d) What’s the probability that those 4 years average less than 30  of rain?