A compression coil spring has a natural $($ie: uncompressed$)$

length of $200$ mm $($Position $1$ in the diagram$)$ The stiffness of

this spring is $4068\frac{N}{m}.$ How much work must be done to

compress this spring from position $2,$ where it is $160$ mm long,

to position $3$ where it is $90$ mm long?

Explain your answer with the help of a force vs extension

graph