You need to find the slope of a line which you find by picking two points then subtracting one y value from the other and subtracting the corresponding x values from each other (ex. (16,4) and (3,6) 4-6/16-3= -2/13. So -2/13 is the slope) for the second question about negative or positive correlation it means if the y value increases does the x value increase as well(or vice versa)? if so then its a positive correlation however if when the y value increases the x value decreases (or vice versa) its a negative correlation . If the dots are just all over the place its no correlation
