Statistical evidence is admissible to establish predominance under FRCivP 23(b)(3) if that evidence would be admissible in an individual action on the same claim, the statistical evidence is linked to the plaintiffs’ theory of liability and the use of averaging assumptions does not conceal the variations that otherwise would defeat class certification. Here, plaintiffs’ statistical evidence satisfied those three tests. statistical evidence is admissible in individual antitrust price-fixing suits to show the individual plaintiff’s damages. The statistical evidence matched the price-fixing theory of liability, and the averaging assumptions did not conceal disqualifying variations, but merely differences in the amount of damages sustained. The district court did not abuse its discretion in concluding that plaintiff’s expert’s evidence, based on regression analysis of prices could be believed by a jury to prove a common 10% upcharge as a result of the price-fixing conspiracy. The mere fact that 5% of a large class might have sustained no damages was insufficient to compel denial of class certification.