The Rathburn Manufacturing Company develops electric wiring, which it sells to contractors in the construction industry. Approximately 900 electric contractors buy wire from Rathburn annually. Rathburn's director of marketing desires to find out electric contractors' satisfaction with Rathburn's wire. He developed the questionnaire that yields a satisfaction score between 10 and 50 for participant responses. A random sample of 35 of 900 contractors is asked to complete a satisfaction survey. The satisfaction scores for 35 participants are averaged to produce the mean satisfaction score.
What would be a parameter for this study?