What is the likelihood that a student will get four or more correct answers simply by guessing on a multiple-choice test with three possible answers for each of the five questions?
A normal population has a mean of 80.0 and a standard deviation of 14.0. Determine the likelihood of a value of 75.0 or less.
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. 1) During what percentage of years does Ithaca get more than 40" of rain? 2) Less than how much rain falls in the driest 20% of all years? 3) A Cornell University student is in Ithaca for 4 years. Let represent the mean amount of rain for those 4 years. Describe the sampling distribution model of this sample mean, . 4) What 's the probability that those 4 years average less than 30" of rain?