Where did the grades for 1/4 of the year and 3/4 of the year come from if they are not entered in the electronic gradebook?

Since teachers rarely enter grades for the 1/4‑year and 3/4‑year periods, EduPage calculates them in the grading statistics.
This means that in the Final Grades view, the grades for the 1/4‑year and 3/4‑year periods are calculated grades. For the half‑year and end‑of‑year periods, this view contains only the grades that were actually entered.

You can learn how ongoing grades/averages are converted into a calculated grade in this guide:
How the final grade in the classification report is calculated?

More guides: Classification statistics