Is there a simple way to straighten this line of vertices? I'm somewhat new to Blender.
I have a simple mesh that I used proportional editing on.
Now I want to straighten out the outer four corner edges.
(ie the selected vertices when the .blend file opens)
I've seen some answers but can't get them to work.
Thanks for any ideas to try.

Here's the copied link to the .blend file:



Thanks for any ideas.

edit: okay, thanks, here's a picture...wondering how to straighten out that line of vertices, thanks again for any ideas

edit:
@Brian, Okay, so now my question is how to make it so, in this second image, these two selected vertices are on an axis? Then I can then select and scale the rest of the line of vertices and scale them to that axis. I don't know how to align these two vertices to any axis. Thanks.

(Well, forget that second image, not enough reputation to post two links, so the vertices I'm talking about are on the left side of the first image, the topmost
vertice, and the fourth up from the bottom.)

@Jesse Can you get the line of vertices I refer to to line up in a straight line between the two vertices I'm referring to with this technique? I couldn't do it.
I think the simplest way would be to scale them along the y axis with your pivot set to "median point".

Select the vertices like you've shown in the picture then press S and then Y. Scale the vertices in and they will perfectly align. You may need to repeat these steps once or twice. Make sure proportional editing is turned off during this process.

Good luck.