P$21\mathrm{.}5$ As at December $31,2023,$ Kendrick Corporation is having its financial statements audited for the first time ever. The auditor has found the following items that might have an effect on previous years. $1.$ Kendrick purchased equipment on January $2,2020,$ for $$117,000.$ At that time, the equipment had an estimated useful life of $10$ years, with a $$9,000$ residual value. The equipment is depreciated on a straight$-$line basis. On January $2,2023,$ as a result of additional information, the company determined that the equipment had a total useful life of seven years with a $$5,400$ residual value. $2.$ During $2023,$ Kendrick changed from the double$-$declining$-$balance method for its building to the straight$-$line method because the company thinks the straight$-$line method now more closely follows the benefits received from using the assets. The current$-$year depreciation was calculated using the new method following straight$-$line depreciation. In case the following information was needed, the auditor provided calculations that present depreciation on both bases. The building had originally cost $$1\mathrm{.}08$ million when purchased at the beginning of $2021$ and has a residual value of $$108,000.$ It is depreciated over $20$ years. The original estimates of useful life and residual value are still accurate. $20232022.2021$ straight line $$48,60048,60048600$ double$-$declining balance $$87,48097,200108,0003.$ Kendrick purchased a machine on July $1,2020,$ at a cost of $$140,000$ and a useful life of eight years. Kendrick$$s bookkeeper recorded straight$-$line depreciation during each year but failed to consider the residual value. $4.$ Prior to $2023,$ development costs were expensed immediately because they were immaterial. Due to an increase in development phase projects, development costs have now become material and management has decided to capitalize and depreciate them over three years. The development costs meet all six specific conditions for capitalization of development phase costs. Amounts expensed in $2020,2021,$ and $2022$ were $$200,$ $$700,$ and $$800,$ respectively. During $2023,$ $$4,200$ was spent and the amount was debited to Deferred Development Costs $($an asset account$).$ Questions: a$.$ Prepare the necessary journal entries to record each of the changes or errors. The books for $2023$ have been adjusted but not closed. Ignore income tax effects and round to the nearest dollar. b$.$ Calculate the $2023$ depreciation expense on the equipment.