Final answer:
The average annual salary of 50 of a company's 800 employees is a statistic, as it is derived from a sample of the population. A parameter, on the other hand, is calculated using data from the entire population, as would be the case if a class's average exam score is computed using all students' scores.
Step-by-step explanation:
The average annual salary of 50 of a company's 800 employees would be considered a statistic because it is a measure derived from a subset (sample) of the larger group (population). When we calculate a statistic, we're usually trying to make an inference about the population from a sample. A statistic helps us estimate the parameter, which is a measure that represents the entire population.
An example of when you would calculate a parameter is if you had data from the entire population. For instance, if a professor calculates the average exam score for her class using the scores of all students, the average is a parameter because it includes the entire group of interest.
In contrast, if the U.S. federal government surveys all high school seniors in the United States and finds that 50 percent were planning to attend a four-year college or university the following year, this 50 percent figure would represent a parameter, as it includes the entire population of U.S. high school seniors.