Univariate Data Univariate Data: involving a single variable Measuring: Center Spread Position

Mean/Standard Deviation Population: µ Sample: X-bar Non Resistant Standard Deviation Measures spread by looking at how far the observations are from the mean. Population: σ Sample: s Also Non Resistant Use when looking at fairly symmetrical distributions that don't have outliers

Median/5 # Summary Median Represented by: M 5 # Summary Min, Q1, M, Q3, Max Basic representation of spread and center. Good for looking at distributions with skewness or outliers. Boxplots IQR: Central box spanning Q1-Q3 (Line in the middle of this box is Median) Lines extending from central box to the smallest and largest observations that aren't outliers Outliers: 1.5 x IQR

Position Percentile: The % of observations that are less than or equal to what we are looking at. (i.e. Jimmothy scored within the 72nd percentile) Standardized scores Z-Score: (Observation – Mean)/Standard Deviation Standardized value that represents how many standard deviations the observation is from the mean. Shouldn't be higher than |2|- |3| (otherwise the value may be considered an outlier).

Sources Notes Textbook http://www.regentsprep.org/Regents/math/ ALGEBRA/AD1/unidat.htm