Plzzz help: The sequence graphed below can be generated using which formula?

Aportion of a line bounded by two points is defined as

Question 5 spring semester final exam math evaluate

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?