Can people better memorize letters if they are presented in recognizable groupings than if they are not?

Can people better memorize letters if they are presented in recognizable groupings than if they are not? Students in an introductory statistics class were the subjects in a study that investigated this question. These students were given a sequence of 30 letters to memorize in 20 seconds. Some students (25 of them) were given the letters in recognizable three-letter groupings such as JFK-CIA-FBI-USA-.... The other students (26 of them) were given the exact same letters in the same order, but the groupings varied in size and did not include recognizable chunks, such as JFKC-IAF-BIU- ... Th e instructor decided which students received which grouping by random assignment. After 20 seconds of studying the letters, students recorded as many letters as they could remember. Th eir score was the number of letters memorized correctly before their first mistake. Th e instructor conjectured that students in the JFK-CIA-... group would memorize more letters, on average, than students in the JFKC-IAF-... group.

1.  Conduct a simulation analysis with 1000 shuffles. Indicate how to determine the approximate p-value from the simulation results and report that p-value.

2. Give a conclusion about the strength of evidence against the null, in context, based on the p-value you obtained in #8.

3. Use the 2SD rule to generate a 95% confidence interval on the long-run difference in means between the two groups.

4. Interpret the 95% confidence interval you obtained in #10.