Figure 1 : Plot of populations of Blue and Red Globular Clusters for 40 galaxies

Statistical tests

Least squares weighted best fit y = c1 * x + c2

Spearman Rank test was used to test probability of correlation

Data set Red Blue

N = 40 c1 c2 spearman rho probability of correlation c1 c2 spearman rho probability of correlation

Full Sample
Blue/Red GC vs.
Velocity Dispersion 0.255 ± 0.057
(4.5 sigma) 0.557 ± 0.135 0.614 99.99% 0.112 ± 0.057
(2.0 sigma) 0.677 ± 0.135 0.423 99.17%

Data set	Red				Blue
N = 40	c1	c2	spearman rho	probability of correlation	c1	c2	spearman rho	probability of correlation
Full Sample Blue/Red GC vs. Velocity Dispersion	0.255 ± 0.057 (4.5 sigma)	0.557 ± 0.135	0.614	99.99%	0.112 ± 0.057 (2.0 sigma)	0.677 ± 0.135	0.423	99.17%