Determine whether each number describes a population parameter or a sample statistic. Explain your reasoning.

(a) A survey of 1000 U.S. adults found that 52% think that the introduction of driverless cars will make roads less safe.

(b) At a college, 90% of the members of the Board of Trustees approved the contract of the new president.

(c) A survey of 727 small business owners found that 25% reported job openings they could not fill.