Final answer:
The sentence provided is a compound sentence; it consists of two independent clauses joined by the conjunction 'and'.
Step-by-step explanation:
The sentence 'Fraser often writes letters to his aunt in Rio de Janeiro and hopes to visit there someday' is a compound sentence. This is because it contains two independent clauses: 'Fraser often writes letters to his aunt in Rio de Janeiro' and 'hopes to visit there someday', which are connected by the conjunction 'and'. Neither of these clauses are subordinate to the other, and each can stand alone as a complete sentence.
When determining the structure of a sentence, it's important to identify the clauses and how they are connected. In this case, the use of a coordinating conjunction (and) to link two independent clauses is what makes this sentence compound.