Explain why the completion % of goods that are in work in process can sometimes be applied to both direct material and conversion costs while in other questions, it only applies to conversion costs. In one question which is linked below, the % completion of ending work in progress is applied to only conversion costs:

https://www.chegg.com/homework-help/questions-and-answers/materials-costs-396000-conversion-costs-209110-charged-processing-department-month-septemb-q38616510?trackid=c4ce46ed05fc&strackid=3b315631a28b

In this question question however, the completion % is applied to both direct materials and conversion costs:

https://www.chegg.com/homework-help/questions-and-answers/assembly-department-uses-process-cost-accounting-system-department-adds-materials-incurs-c-q62664153?trackid=499799200bd0&strackid=ec790ffb86c0