One space.

Akin to using the tab button instead of typing 5 spaces.

Word: Find "space space" and replace with "space." Repeat until all extra spaces are gone.

Automatically adjusted space after period. Less possibility of white rivers down the page. More words per line. No excessive space after period when using full justification. Standard for publishers.

Type how you wish to type. Your editor will fix it for you so that it looks more professional.

We do this frequently for our state legislature. Bills typically require all numbers to be written out. Our local gross receipts tax, for example, has 4 decimal places.

Four and Nine Hundred and Seventy-Five Thousandths percent

To use "of a percent" (not recommended):
Four percent and Nine Hundred and Seventy-Five Thousands of a percent

There are . . . .

1. Even though a singular word is closer to the verb, the verb is referring to 2 things: progress and improvement. Being close to the verb has nothing to do with this.

2. Often, something sounds right simply because we are accustomed to hearing it wrong. Example: "The data is correct" may sound right, but it isn't.

3. Whether or not "improvements" is plural is irrelevant. The verb is referring to two things. We use "are" when referring to more than one thing.

4. See #3. Also, the second example given as a correct version is a run-on sentence.

5. Yes.

6. That doesn't answer the question. The verb is/are is referring to two things (i.e., progress AND improvement). We use "are" when referring to more than one thing.

7. Yes. (Random Person has the right idea but for the wrong reason).