Problem 2 : Analysis of Warranty Footnote (all amounts are in thousands). The following is the footnote from Apple 202110K : (all amounts are in thousands) Warranty Costs The Company generally provides for the estimated cost of hardware and software warranties in the period the related revenue is recognized. The Company assesses the adequacy of its accrued warranty liabilities and adjusts the amounts as necessary based on actual experience and changes in future estimates. Note 10 - Commitments and Contingencies Accrued Warranty and Guarantees I he tollowing table shows changes in the Company's accrued warranties and related costs for 2021, 2020 and 2019 (in millions): Warranty expense / product sales $2,684= est of #defective units x est $cost/ unit to repair or replace Product sales for 2019,2020 and 2021 was $213,883,$220,747, and $297,392, respectively. (amounts in millions). a. How much warranty expense did Apple recognize in 2021? What effect did this have on the BSE? b. What was the cost to Apple to fulfill warranties during 2021 ? What effect did this have on the BSE? c. What could explain the difference between the Warranty expense / product sales \% over the three year period