I'm having a problem. I can render and export in any format at .300 dpi, except for .png. I like using the .png format because it leaves just the figure and not the background, but when I export as a .png file, it saves it at .118 dpi and when I resize it to .300 dpi, it's only half the size. 

I've posted in a few places, but I'm not finding anyone else who has the problem. Any suggestions?