Double-spacing won't save in .doc & .docx files
No matter what program I use, no .doc or .docx file i create will save with double line spacing, making it impossible to create MLA-type papers for college. No combination of creating other formats and saving as .doc/.docx has worked, and neither has moving between programs; the problem persists in Pages, TextEdit, and Document Writer Pro. As soon as I save a .doc/.docx file with double-spacing, I can go into Finder and preview the file and see that it was saved without double-spacing. I've tried deleting the relevant preferences file for TextEdit in the Library folder, to no avail. I've also tried changing the default settings in each program to include double line spacing, which makes no difference in the saved file. I'm able to create other files (.rtf, .pages, etc) just fine, but I have to turn in .doc or .docx files for college.
Mac Pro, macOS Sierra (10.12.3)