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QUESTION 4 The depression scores {the higher the score, the more stressed are the patients) of 25 patients were recorded before and after they had undergone a therapy. The scores were analyzed to see the effectiveness of the therapy. The outputs are indicated below. Paired Samples Statistics Mean N Std. Deviation Std. Error Mean Pair 1 depres 42.56 25 4331 .866 de m2 41.36 25 4.95? .991 Paired Samples Test Paired Differences t df Sig. Mean Std. Std. Error 95% Condence (2tailed] Deviation Mean Interval ofthe Difference Pair 1 depress1 depressZ X 2.121 . . Note: depresst is representing the depression scores before the patient undergo a therapy Assuming the score of depression is normally distributed. a} nd the values of X and Y. (3 marks} b} State the 95% confidence interval for the mean depression scores. (1 mark] c} Based on the confidence interval in b], can it be concluded that the therapy is effective? (2 marks}