STAB22H3 Lecture Notes - Lecture 3: Standard Deviation, Linear Map, Histogram
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STAB22H3 Full Course Notes
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Lec 03: the standard deviation as a ruler and the normal model. Effect of a linear transformation on summary statistics: Multiplying each observation in a data set by a number b multiplies the mean, median, by b and the measures of spread (standard deviation, iqr) by abs (b), where abs represents the absolute value. Adding the same number, a to each observation in a data set adds a to measures of center, quartiles, percentiles but does not change measures of spread. If x is an observation from a distribution that has mean and sd s, the standardized value of x is. A standardized value is often called a z-score. Z-score: tells us how many standard deviations the original observation falls away from the mean: standardizing: calculating a z-score sometimes called standardizing, and helps eliminate units. Density: is a mathematical function that describes the overall pattern of a distribution.
