This document defines and explains several key statistical concepts: - Statistics is the study of collecting, analyzing, and presenting quantitative data. It involves planning data collection through surveys and experiments. - The mean is the average value of a data set, calculated by summing all values and dividing by the number of values. - The median is the middle value when data is arranged in order. For even data sets, the median is the average of the two middle values. - The mode is the most frequently occurring value in a data set. - Standard deviation measures the variation or dispersion of data from the mean. It involves subtracting the mean from each value, squaring the differences, summing them, and taking the square