3. Suppose a new intervention to improve the quality of life of HIV positive patients is developed, and it is studied in an experimental study involving the same patients in this sample. Some patients received this new intervention (experimental group), while some received no intervention (control group). Consider the mean number QALY's calculated in question 2b to be the baseline measure of quality of life before the intervention is implemented for both groups. Twenty years later the quality of life of these patients is measured again, and at the conclusion of the study, the investigators measured the final mean QALYs in both groups. Table 1 below shows the results of this experiment. Table 1. Number of QALYs at baseline and 20 years after the implementation of a new intervention to improve the quality of life of HIV positive patients. QALYs at baseline QALYs at study end Statistical Significance xperimental group Use your answer in 18 p = 0.042 for a t-test for question 2b above independent samples control group Same as 13.5 experimental group a) Calculate the overall mean change in QALY that resulted from the experimental treatment. NOTE: First calculate the mean change in QALY for the experimental group (i.e., QALYs at study end minus QALY at baseline), then do the same for the control group. Next, subtract the mean change in QALY for the control group from that of the experimental group. This is the overall mean change. b) Given the p-value in the final column, did the experimental treatment have a significant effect (explain your reasoning)