How to Determine the Masses of Objects from an Acceleration vs. Force Graph?

[ScullyX51]

Homework Statement

The figure (Intro 1 figure) shows an acceleration-versus-force graph for three objects pulled by rubber bands. The mass of object 2 is 0.150 kg. What are the masses of objects 1 and 3?
(I've attached the figure...hopefully it will show up)

Homework Equations

F=ma

The Attempt at a Solution

I'm super lost on this one...could use all the help I can get!

 

[LowlyPion]

Homework Statement

The figure (Intro 1 figure) shows an acceleration-versus-force graph for three objects pulled by rubber bands. The mass of object 2 is 0.150 kg. What are the masses of objects 1 and 3?
(I've attached the figure...hopefully it will show up)

Homework Equations

F=ma

The Attempt at a Solution

I'm super lost on this one...could use all the help I can get!

F = M*a

This means that

$$F_{(a)} = m * a$$

That means that the slope of the F is the mass as in

$$\frac{dF_{(a)}}{da} = m * \frac{da}{da} = m$$

So if the slope of 2 is given as .15 kg and on the graph it has a slope of ...?
Then the slope of 1 and 3 compared to 2 should reflect their masses.