Several statistical software sites exist on the Internet

Several statistical software sites exist on the Internet. They are Web based (no download), no cost, and incredibly easy to use. One such site is Vassar Stats at http://faculty.vassar.edu/lowry/VassarStats.html, and another is Stat Crunch at http://www.statcrunch.com/. I have used both very reliably for years. Explore Vassar Stats and then analyze these data from a hypothetical study of sleep’s influence on memory:

Memory scores for the eight-hour group are 9, 7, 6, 7, 9, 6, 5, 5, 9, 8; memory scores for the four-hour group are 6, 3, 2, 1, 3, 3, 7, 2, 4, 4. Click “t-Tests & Procedures” on the Vassar Stats home page. Then click “t-Test for Independent Samples.” Enter the scores under “Data Cells” and click “Calculate.” What are the means? What was the calculated t value (two tailed)? (Hint:

Did you get 4.67, I hope?) What is your decision about the null hypothesis? Are the means significantly different?