represents points as curve

the following table gives the force *F* newtons which, when applied to a lifting machine overcomes a corresponding load of *L* newtons.

Force *F* newtons 25 47 64 120 149 187

Load *L* newtons 50 140 210 430 550 700

choose suitable scales and plot a graph of *F* (vertically) against *L* (horizontally) Draw the best straight line through the points. Determine from the graph (a) the gradient (b) the *F*-axis intercept (c) the equation of the graph (d) the force applied when the load is 310N (e) the load that a force of 160N will overcome (f) if the graph were to continue in the same manner, what value of force would be needed to overcome a 800N load?

this is how i have plotted the graph

http://i111.photobucket.com/albums/n...v_k/img001.jpg

from this i have worked out questions (a)(b)(d)(e)

(a)0.6896551724

(b)12.5 Newton's

(d)84N

(e)637.5N

if you think that any of these are wrong please tell me

i need help on (c) & (f)