i need help...
i'm having trouble figuring out how to compute correlations using the Pearson Product-Moment Correlation Coefficient. if anyone can help me with this, i'd be eternally grateful. it seems fairly simple when you just glance at the formula, but i'll explain.
let's assume that we are looking for the strength of the correlation between height and weight in human beings. we'll take 20 test subjects, and N = number of subjects. for each subject, X = height in inches, Y = weight in pounds. for those of you unfamiliar, Σ stands for "the sum of".
here's where i lose my understanding: assume that "N" is equal to the number of test subjects, "ΣX" is the sum of all height values, and "ΣY" is the sum of all weight values. that being said, what do i plug in for "Y" in "NΣXY"?