Hi, I believe the answer is Donna makes 0.2 revolutions per foot of distance traveled and the slope of the graph is 1/5.
To find the number of revolutions per minute you find a point on the graph where the <em>x</em> line and the <em>y</em> line match up, such as (2, 10) then you divide the amount of revolutions in ten feet by ten to find the amount in just one foot, 0.2.
To find the slope of the graph you pick two points on it such as (2, 10) and (4, 20) and subtract the first y coordinate from the second (4 - 2) and do the same with the x coordinates (20 - 10). Then you divide the difference in the y coordinates by the difference in the x coordinates to get the 2/10, then simplify to get 1/5.
Hope this is helpful and not too drawn out :)
