A psychologist is examining the efficacy of a stress reduction intervention for a group of 25 individuals. The participants' stress levels are measured before they undergo the intervention and then again after completing a four-week stress management program. To evaluate whether there's a statistically significant difference in stress levels before and after the program, which type of hypothesis test should the psychologist employ?

QUESTION 13 A psychologist is examining the efficacy of a stress reduction intervention for a group of 25 individuals. The participants' stress levels are measured before they undergo the intervention and then again after completing a four-week stress management program. To evaluate whether there's a statistically significant difference in stress levels before and after the program, which type of hypothesis test should the psychologist employ?