F x (x + h) - fx/h
fx +fh - fx /h
fh/h
f
So f is the answer
The question is asking you to organize the data in line plot form. to do so you must create a number line (which in this case is provided for you) and put X's above the numbers. for example lets say your given the following data :
1, 2 ,2 , 4 , 1 , 3 , 2 , 5
this is how you would graph it in line plot form
x . x
x . x . x . x . x
_________________________________________
1 . . . 2 . 3 . 4 . 5
but in your case not al the numbers listed are on the plot so instead you do this:
x . x
x . x . x . x . x
___________________________________
1 . 3 . 5 .
plot as if the numbers are there. ( as usual spacing is important)