What are the values of m and n in the matrix addition below ? Help pls

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?

25 ! the line of best fit is h = 5a + 86. predict the height at age 16. show your work.

Which one ? is the answer and how to find this answer