Lorin Management Services has an unfunded postretirement benefit plan. On December 31, 2011, the following data were available concerning changes in the plan's accumulated postretirement benefit obligation with respect to one of Lorin's employees:
APBO at the beginning of 2011 $ 40,000
Interest cost: ($40,000 × 10%) 4,000
Service cost: ($92,000 × 1/23) 4,000
Portion of EPBO
attributed to 2011
APBO at the end of 2011 $ 48,000
What is the expected postretirement benefit obligation at the end of 2011?