1.5 Take-Home Points

• Values of a sample statistic vary across random samples from the same population. But some values are more probable than other values.

• The sampling distribution of a sample statistic tells us the probability of drawing a sample with a particular value of the sample statistic or a particular minimum and/or maximum value.

• If a sample statistic is an unbiased estimator of a parameter, the parameter value equals the average of the sampling distribution, which is called the expected value or expectation.

• For discrete sample statistics, the sampling distribution tells us the probability of individual sample outcomes. For continuous sample statistics, it tells us the probability density, which gives us the probability of drawing a sample with an outcome that is at least or at most a particular value, or an outcome that is between two values.