{30, 30.25, 30.5, 30.75, 31, 31.25, 31.5, 31.75, 32} would be the correct answer.
I'm sure you searched for this answer elsewhere and got either {30, 30.25, 30.5, 30.75, 31, 31.25, 31.5, 31.75, 32} or {30, 31, 32}, while they are both similar answers and would probably both make sense, however, there is a keyword in the question that gives us the reasoning behind the correct answer.
Reread the question and pay attention to the bold text:
Vonda works between 30 and 32 hours per week at a hair salon. She pays a one time $250 chair rental fee, and earns $40 per hour that she works. The hours she works are rounded to the nearest quarter hour.
Meaning that the hours (X values) that she works are rounded to the nearest quarter, which would eliminate {30, 31, 32}, because it does not include the quarters (.25 , .50 , .75)
Hopefully I helped.
: )