In 1-3sentences describe the difference between asampleand apopulation.Be sure to explain each term and how they relate.

Define random and nonrandom samples.Be sure to indicate their general differences.Define each term generally without including explanations of specific types of sampling (i.e.,do not define specific accidental or stratified sampling).Answer in less than 5sentences.

Researchers can construct a sampling distribution of means, a frequency distribution of a large number of random sample means that have been drawn from the same population. This distribution has the following characteristics:

1. The sampling distribution of means approximates a________ curve.

2. The mean of a___________ (the mean of means) is equal to the true population mean.

3. The standard deviation of a sampling distribution of means is______________ (smaller or larger?)than the standard deviation of the population.

In 2-5sentences, 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)?

In 5sentences or less,define confidence interval and explain 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___________