grammar - 食べたそうだ vs. 食べそうだ, 静かだそうだ vs. 静かそうだ

I saw this as a comment on this question, Why does そう in 「美味しいそう」 not mean "seem" the way I think it should?「美味しいそう」-not-mean-seem-the-way-i-think-it-should,

and would love to understand the differences.

I am sure I will mangle the translation, so forgive me.

食べたそうだ Looks like he ate it.

食べそうだ Looks like he will eat it.

静かだそうだ I heard that it's quiet.

静かそうだ Seems quiet.

If anyone would be kind enough to explain the differences in meaning and usage, I would greatly appreciate it. I didn't learn how to embed the quoted question, so sorry again for that.