A researcher studies the effect of a drug (MAO inhibitor) on the number of nightmares occurring in veterans with post-traumatic stress disorder (PTSD). A sample of PTSD clients records each incident of a nightmare for 1 month before treatment. Participants are then given the medication for 1 month, and they continue to report each occurrence of a nightmare. For the following hypothetical data, determine whether the MAO inhibitor significantly reduces nightmares. Use the 0.01 level of significance and a one-tailed test.

Number of Nightmares
1 Month Before Treatment	1 Month During Treatment
6	1
9	1
5	5
10	10
10	5

Complete the following. M_D = 1 (Use 3 decimal places.) Compute SS, sample variance, and estimated standard error.

SS =	2 (Use 3 decimal places.)
s2 =	3 (Use 3 decimal places.)
sMD =	4 (Use 3 decimal places.)

Compute t-critical and t. (Use 3 decimal places.)

t-critical =	5
t =	6

Conclusion Fail to reject the null hypothesis, the treatment does not significantly reduce nightmares. Reject the null hypothesis, the treatment does significantly reduce nightmares. Fail to reject the null hypothesis, the treatment does significantly reduce nightmares. Reject the null hypothesis, the treatment does not significantly reduce nightmares.