(Solved): How to solve for the angle of an inclined plane, given a graph of a straight line where the x-axis i ...

How to solve for the angle of an inclined plane, given a graph of a straight line where the x-axis is the coefficient of static friction between a body and the plane, while the y-axis is the applied force on that body up the plane. Line has equation (5.33 - 1.74) / (0.51 - 0) as given points. Slope-intercept form is y=7.04x+1.74. It is also specifically stated that the applied force at every point on the line is the minimum force required to prevent the body from sliding down the plane.

Answer is needed as angle in degrees. Explanation of the process would be most helpful.

In the first figure here, a sled is held on an inclined plane by a cord pulling directly up the plane. The sled is to be on the verge of moving up the plane. In the second figure, the magnitude $F$ required of the cord's force on the sled is plotted versus the coefficient of static friction ${?}_5$ between sled and plane: $F_1=1.74\mathrm{N},F_2=5.33\mathrm{N}$, and ${?}_2=0.510$. At what angle $?$ is the plane inclined?