What is the null hypothesis?What is the alternative hypothesis?Is the alternative hypothesis directional or non directional (one tailed or two tailed)

Scenario Researchers want to study effectiveness of anxiety treatments in elderly patients. . They design a study with 3 groups to which participants are randomly assigned: o a group where participants receive 6 weeks of cognitive behavior therapy (CBT), o a group where participants receive 6 weeks of CBT and are also treated with alprazolam, o and a group where participants are put on a waitlist for 6 weeks (and therefore receive no treatment for the moment). . For ethical reasons, those waitlisted participants will later be given a treatment, if they so desire, but such treatment will not be part of the study. . The researchers recruited 120 older adults with a diagnosis of generalized anxiety disorder. They collected some basic demographic information from these adults, including sex, age, and education. . At the end of the 6 week study, they administered the Beck Anxiety Inventory (BAI) to determine anxiety levels; they also obtained a Full-Scale IQ (FSIQ). The researchers predict that the CBT therapy will mitigate (somewhat reduce) anxiety symptoms as compared to the waitlist (control) group, and that the group that receives the CBT and alprazolam will have fewer anxiety symptoms than the CBT-only group