After you graduate from college, do you plan to stay at your next full-time job for 35

Question:

After you graduate from college, do you plan to stay at your next full-time job for 3–5 years? In a survey of 13,127 randomly selected graduating college students, 43% said yes. Researchers then made an inference about all graduating college students.
a. Define a variable for the study.
b. Identify the sample.
c. Identify the population.