7. Data from a study on "social distress" shows that activity in an area of the brain that responds to physical pain goes up as distress from social exhaustion goes up. (16 pts) The linear regression equation shown by a calculator is: (where y represents brain activity and x represents social distress) y = atbx a= -0.122 b= 0.063 r-=0.766 7=0.875 (a) Is the association of brain activity and social distress positive or negative? (d) Use the equation to predict brain activity for a social distress score of 2.5. (c) Which number indicates the strength of this linear relationship? What is it called