A study if the impact of stress on the amount of beta-endorphins released in the blood was reported. Researchers took beta-endorphin levels for 19 patients 12 hours before surgery and again 10 minutes before surgery. If you assume that time before surgery (12 hrs vs. 10 minutes) is a manipulation of stress, does the data indicate that stress affects beta-endorphin levels in the blood? Use a two tailed hypothesis alpha =.05. The data are below.

Insert the mean and SD for the 12 hour and 10 minutecondition below

Subject12 hours10 minutes

1106.5

26.514.0

38.013.5

412.018.0

55.014.5

611.59.0

75.018.0

83.542.0

97.57.5

105.86.0

114.725.0

128.012.0

137.052.0

1417.020.0

158.816.0

1617.015.0

1715.011.5

184.42.5

192.02.0

Calculate Cohen's D and state the meaning of the Cohen's D that you found in the words of the problem.

Cohen D (use SD of 12 hours)=

(3) Cohen's d =

(3) State your conclusions in the words of the problem.

NOTE: take 1 point off for each mistake