Another way to investigate the effectiveness of the intervention described in Exercise 7.25 would be to note that the mean quality of life score before the intervention was 4.47 with a standard...

Another way to investigate the effectiveness of the intervention described in Exercise 7.25 would be to note that the mean quality of life score before the intervention was 4.47 with a standard deviation of 1.18. The quality of life score was 5.03 after the intervention with a standard deviation of 1.01. The sample size was 135 at each time. What do these data tell you about the effect of the intervention? (Note: You don’t have the difference scores, but assume that the standard deviation of difference scores was 1.30.)