GGR270H1 Lecture Notes - Covariance, Standard Score, Standard Deviation
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GGR270&Lecture& & October&3,&2012&
Where: s standard deviation. X is each value in the data set. Is the mean of all values in the data set: z scores. Consists of pairs of variables such as years of schooling or income. Positive: as x increases, y increases. Negative: as x increases, y decreases; as y increases, x decreases. Neutral: absolutely no association/relationship between variables; no direction: strength of the bivariate relationship. Perfect association: the variables move in the same direction; positive or negative; as x increases by 10% y increases by. 10%; absolutely perfect relationship between variables. Weak association: the weaker the relationship, the more scattered the plot. No association: blob of point; no direction; no strength; no relationship between the variables: correlation coefficients. More rigorous approach to observing and measuring strength and direction of a bivariate relationship. Most constructed have a maximum value of +1. 0 and can be positive or negative: +1. 0 perfect positive relationship. Most common measure is pearson"s product moment.