Researchers hypothesize that a certain stimulant makes visual reaction time faster. They recruited 9 participants for a study, and measured each person's visual reaction time (in milliseconds) before and after being given the stimulant. The results are given in the table below.

	1	2	3	4	5	6	7	8	9	mean	sd
Before stimulant	245	278	234	211	251	305	227	265	313	258.778	34.716
After stimulant	232	275	240	202	250	297	209	278	301	253.778	36.228
After - before	-13	-3	6	-9	-1	-8	-18	13	-12	-5	9.823

If necessary, round your answers to the nearest thousandths place (3 decimal places).

1. If uD is the mean difference in reaction time (the mean of After - Before), what hypotheses should the researchers use?

2. What is the value of the t test statistic the researchers can use to answer their question?