lecture 7.5 zscore correlation

lecture 7.5 zscore correlation - Calculation of Pearsons r...

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Calculation of Pearson’s r with the z Score Formula: A quick note at the outset - you would never calculate r using the z Score formula when you have access to the raw scores. Other formulas are easier to work with. Nonetheless, the z Score formula does a nice job of illustrating the mechanics of positive vs. negative correlation, so it’s worth working through. You can also use this to practice calculating z Scores and getting comfortable with multi-step statistical algorithms. Begin with the following sample data set of paired x and y scores: x y 6 4 8 5 6 5 7 6 4 3 5 3 8 5 9 6 4 4 After constructing a scatterplot to verify that the relationship is linear (approximating a straight line), the next step in this case is to transform the raw scores using the z Score formula. In order to do this we first need to calculate the sample means and sample standard deviations (using n-1 in the denominator) for each variable x and y . Once this is done, the product of each z -transformed xy pairing is calculated. The values you should
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lecture 7.5 zscore correlation - Calculation of Pearsons r...

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