Parameters vs Statistics

A company has developed a new phone battery whose average lifetime is unknown. In order to estimate this average, 100 phone batteries are randomly selected from a large production line and tested; their average lifetime is found to be 15 hours. The 15 hours represents a:

A study is under way to determine the average height of all 32,000 adult pine trees in a certain national forest. The heights of 500 randomly selected adult pine trees are measured and analyzed. The parameter in the study is: