what is the value of the correlation coefficient?

Question

A researcher measures the relationship between narcissism and willingness to help. If SS_xy=240, SS_x=320, and SS_y=410, what is the value of the correlation coefficient?

Answer 1

Ashley,

 

Since you give no data for the means of x & Y, I'll assume them to be zero (i.e., ∑x_i = 0 = ∑y_i.) >  then the correlation coefficient, r, simplifies to:

 

r = SS_xy /[(√SS_x)(√SS_y)] = 240 / [(√320)(√410)] = 240 / [(17.8885)(20.2485)] 

r = 240 / 362.2145  =  0.663