"Your education means a lot."
Translation:La tua educazione significa molto.
The English word "mean" has two senses: "to signify (have a meaning)" and "to matter." So does the Italian word "significare." How one interprets that word makes a difference in how one understands "a lot" and "molto." In one sense we have an adjective that must agree with the subject; in the other we have an adverb than does not. It makes no difference in English, but in Italian we could have either "molta" or "molto." Fortunately, there is a fixed phrase "significare molto" which means "to matter a lot," so that issue is settled.
"Educazione," however, is not so clear-cut. "Istruzione" is the more normal way of talking about what English calls education. There are other Italian words that have a similar meaning: "formazione," "studi," "pedagogia," or even "insegnamento." All of these can be considered important. I see no reason for Duo to prefer "educazione." Probably all of these should be accepted.
However, this troublesome sentence seems to be a good one, so long as we can explore and understand the issues it raises.