I need help finding 1-4. I do not understand how to do the steps

Actuary and trustee reports indicate the following changes in the PRO and plan asets of Douglas Roberts Indus tries during 2018 E 17-16 Determine and record pension expense and Gains and losses tunding and retire benefits 017-6, 017-7 $20 million Prior service cost at Jan 1, 2018. from plan amendment at the beginning of 2015 (amortization: $4 million per year Not loss-ADCI al Jan. 1. 2018 previous losses exceeded previous gains Average remaining service le of the active employee group Actuary's discount rate SBO in 10 years in millions) Plan Ats $600 $400 PBO lleginning of 2018 Service cost Interest cost, Loss gain on PBO Less: Retiree benefits End of 2018 Beginning of 2018 Return on plan assets, 3% (10% expected] Cash contributions Lees: Retiree benefits End of 2018 $670 $484 Required 1. Determine Douglas Robert's pension expense for 2018, and prepare the appropriate journal entries to record the expense. 2. Prepare the appropriatural entry) to record any 2018 gains and losses 3. Prepare the appropriate journal entry to record the cash contribution to plan assets. 4. Prepare the appropriate journal entry to record retiree benefits