Answer:
its 17degree as it is supplement to 163
Yes it is.
F1 = k q1 * q2 / r^2
F2 = k *(2*q1) * (4.8 q2) / (7.2 r^2)
Work on F2 for a moment.
F2 = k * 9.6 (q1*q2) / 51.84
F2 = (9.6/ 51.84) * k * q1 * q2 / r^2
Since k * q1 * q2/r^2 is the same in both questions let kq1*q2/r^2 = m
F1 = m
F2 = 0.18 m
So to make it easier F2/F1 = 0.18m / m
F2/ F1 = 0.18 the m's cancel.
And that should be how you do the question.
ANSWER
The function if the graph is,

EXPLANATION
We want to write the function for the graph that, goes through (1,8) and (0,2).
Let the function be of the form

Where m is the slope and

is the y-intercept.
The slope is

The equation becomes,