Mean value: Also known as the average, it is calculated by summing up all individual values in a dataset and dividing it by the total number of values.
Sampling variability: The natural variation that occurs when different samples are taken from the same population; it can affect how closely a sample's average matches the national average.
Population parameter: A characteristic or measure (e.g., mean, proportion) of an entire population, often represented by Greek letters like ฮผ for mean and ฯ for proportion.