Brent is trying to figure out the relationship between the number of times his friends post on social media and their grade point averages. he records the collected data on a scatter plot. which of the linear functions best models the line of best fit? what does the slope in the equation represent?

a) y = 0.004x - 4; the average number of posts per friend

b) y = -0.5x - 4; the amount of decrease in the gpa for each post

c) y = 0.05x - 4; the amount of increase in the gpa for each post

d) y = -0.004x + 4; the amount of decrease in the gpa for each post