You wish to test the following claim (Ha) at a significance level of a = 0.002. For the context of this problem, Had = /2 - /1 where the first data set represents a pre- test and the second data set represents a post-test. Ho: Hd = 0 Ha: Hd # 0 You believe the population of difference scores is normally distributed, but you do not know the standard deviation. You obtain pre-test and post-test samples for n - 40 subjects. The average difference (post - pre) is d = 17.2 with a standard deviation of the differences of Sa = 36.3. What is the test statistic for this sample? (Report answer accurate to three decimal places.) test statistic = What is the p-value for this sample? (Report answer accurate to four decimal places.) p-value =