Descriptive Statistics Summary

Statistics · Axiom Academy

SUMMARY Descriptive Statistics Summary Let's review the key concepts from descriptive statistics, including data types, measures of center and spread, and data visualization techniques. Categorical (Qualitative): Data that describes characteristics or qualities, such as colors, names, or categories (e.g., gender, blood type, favorite sport) Numerical (Quantitative): Data that represents measurable quantities expressed as numbers Discrete Data: Countable numerical values with gaps between possible values (e.g., number of students, dice rolls) Continuous Data: Measurable values that can take any value within a range (e.g., height, temperature, time) Mean (x̄): The arithmetic average of all data values, calculated by summing all values and dividing by the count Median: The middle value when data is ordered from least to greatest; resistant to outliers Mode: The most frequently occurring value(s) in a dataset; can have multiple modes or no mode When to Use Each: Mean for symmetric data, median for skewed data or outliers, mode for categorical data Range: The difference between the maximum and minimum values (Range = Max - Min) Interquartile Range (IQR): The spread of the middle 50% of data (IQR = Q3 - Q1); resistant to outliers Variance (s²): The average of squared deviations from the mean; measures overall variability Standard Deviation (s): The square root of variance; measures typical distance from the mean in original units

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