The Concept of Testing Two Populations
Many statistical studies involve comparing the same parameter, such as a mean, between two different populations. For example:
◆ Is there a difference in average SAT scores between males and females?
◆ Do “long-life” light bulbs really outlast standard light bulbs?
◆ Does the average selling price of a house in Newark differ from the average selling price for a house in Wilmington?
To answer such questions, we need to explore a new sampling distribution. (I promise this will be the last.) This one has the fanciest name of them all—the sampling distribution for the difference in means. (Dramatic background music brings us to the edge of our seats.)
The sampling distribution ...