I'm stuck on a mechanics question I have to do for homework:

A block of mass 4KG is at rest on a plane inclined at 35 degrees to the horizontal, under the action of a force of magnitude PN acting up the plane. The coefficient of friction between the block and the plane is 0.45. Find the range of possible values for P.

I've tried resolving the forces horizontally and vertically, but can't work out how i'm supposed to find a range of values.

Thanks