A psychologist randomly assigned college students to two groups. All participants were asked to avoid caffeine for hours before a cognitive test. At , Group A was given a cup of coffee, while Group B received a placebo beverage. Both groups then completed a memory recall task involving a list of words. The response variable was the number of words correctly recalled. Group A had a mean recall of words, and Group B had a mean recall of words. The researchers also checked that the groups did not differ in baseline anxiety or sleep hours. Before the test, participants reported their alertness level, and Group A was found to be significantly more alert than Group B. What are the statistics in this study?
