Dist. Ct. did not err in granting plaintiffs’ motion for summary judgment in class action alleging that defendant-pension plan violated ERISA by using projection rate in instant cash balance plan that was too low when class members took lump sum payment of pension benefit. Record showed that defendant used 30-year Treasury bond rate, which was lower than greater of either 4% rate or rate measured by 75% of defendant’s plan investment returns, that were mentioned in plan. Moreover, Dist. Ct. could use 8.2% projection rate, which was based on expert testimony, and defendant could not retroactively amend terms of plan to effectively lower projection rate. However, defendant could assert 6-year statute of limitations defense for those class members, who took lump sum payments more than 6 years prior to filing date of instant lawsuit.