Flagg Corp purchase and placed into service $$3\mathrm{.}3$ million worth of virology testing equipment on March $31,2021.$ The equipment is expected to last $6$ years and$/$or $2$ billion batches, and have a salvage value of $$450,000.$ Calculate the depreciation expense for $2021,2022,$ and $2023$ for the following methods:

$1\mathrm{.}1$: Straight$-$line.

$1\mathrm{.}2$: Sum of the year$$s digits.

$1\mathrm{.}3$: Triple declining balance.

$1\mathrm{.}4$: Units of production $($assume $650$M$,850$M and $600$M batches in years $2021,2022,$ and $2023).($go out to six decimals on the cost per unit$)$

$1\mathrm{.}5$: Assume Flagg Corp used the straight$-$line method. On January $1,2024,$ Flagg Corp determined the equipment would generated net free cash flows $($undiscounted$)$ of $$350,000,$ $$300,000$ and $$250,000$ in each of the next $3$ years and nothing thereafter. Further, Flagg Corp uses an internal interest rate of $19\%.$ If necessary, record the impairment journal entry as of January $1,2024.$