Answer:
Avondale Lumber
Calculation of Inventory Amounts at the end of each year:
= Inventory cost divided by the Index:
2021:    = $408,450/1.05 = $389,000
2022:   = $420,740/1.09 = $386,000
2023:   = $478,500/1.10  = $435,000
2024:   = $513,585/1.13   = $454,500
Explanation:
a) Data and Calculations:
Year Ended           Inventory Cost     Index     Year-End Costs
                                                                          (Relative to Base Year) 
2021                         $ 408,450         1.05        $389,000 (408,450/1.05)
2022                           420,740          1.09       $386,000 (420,740/1.09)
2023                           478,500          1.10        $435,000 (478,500/1.10)
2024                           513,585           1.13       $454,500 (513,585/1.13)
b) The conversion of the ending inventory cost to the base year with an index is obtained by dividing the inventory cost by the index.  This gives a cost that is relative to the base year.