Final answer:
The sentence "Only 50 percent of the students have said they want to study Spanish or any other language, so statistics show a lack of interest..." is an opinion disguised as fact.
Step-by-step explanation:
The sentence that is an example of an opinion disguised as fact is: "Only 50 percent of the students have said they want to study Spanish or any other language, so statistics show a lack of interest in spite of Octavio Peterson's rhetorical claims." This sentence presents the author's interpretation of the statistic as a definitive lack of interest, which is subjective and not an established fact. The use of the phrase 'statistics show' suggests a factual basis, but the conclusion drawn is the author's opinion on how the statistic should be interpreted.