define thestandard error of themean.Include in your definition thepurpose of the standard error of the mean in statistics and how one would go about estimating the standard error of the mean.

What do degrees of freedom indicate in regards to thetdistribution (i.e.,the normal distribution)?

What is confidence interval and its practical use in statistics.

An administrator in charge of undergraduate education on a large campus wanted to estimate the average number of books required by instructors. Using bookstore data, she drew a random sample of 25 courses for which she obtained a sample mean of 2.8 books and a sample standard deviation of .4. Construct a 99% confidence interval to estimate the mean number of books assigned by instructors on campus.

t=_________

99%confidence interval = _________ to___________