The graph below depicts the length of a spring vs. the weight suspended from it. Construct a good straight-line model for this data and use your model to determine the length of the spring when weight 56 grams is suspended. Determine also the weight required to achieve length 20 cm. The x axis is marked in units of 7 grams and the y axis in units of 22 cm, both starting at (0,0).

Interpret both the x and the y intercepts of this graph.