Final answer:
The informal part to change in the sentence is 'for-real.' It should be replaced with a formal term like 'actually' or 'genuinely.' Using precise language and avoiding slang ensures appropriateness in academic and formal contexts.
Step-by-step explanation:
The part of the sentence that is informal and needs to be changed is "I was for-real sick yesterday and had to miss school." The informal phrase here is "for-real," which should be replaced with a more formal term to fit a standard written or professional communication style. Instead, you could say, "I was actually sick yesterday and had to miss school."
Informal language, like the phrase "for-real," is often appropriate in casual conversation. However, in academic and formal settings, it's important to use a more formal tone. For instance, phrases such as "the folks," "hooked on," "went," "dude," and "chilled for a while" from the reference sentences provided, should all be revised for formality. Alternatively, sentences like "Mr. Gonzalez quickly reprimanded the student for using his cell phone in class," exhibit the use of formal language suitable for academic and professional contexts.
To maintain a formal tone, it is also wise to avoid contractions and choose words that are more precise. For example, using "I was genuinely sick yesterday and had to miss school" would be more appropriate in a formal setting. The word "genuinely" expresses sincerity and is a term widely accepted in formal writing.