please explain how to get the formulas in the gray boxes

$8111210$ Hegnning Balance$13|1419202222315$ Total purchased$16$ Total avalable$17$ Sales$19$ Endng batance$2728293031$Data SectionPurchase$3724|$Cost of goos soid$25$ Ending iventory cost$26$ Total goods avalabie$40$DateMarMay $1343$ALKg $28$Nov $2032$ Sales$4633$ Cast of goods sold$34$ Gross proft$35|$Taxes $(40\%)36$ INet ncome$49$Calculations$41$SalesAnser Secton$44$ Less taces$45$ Less dvidendsCuantityUnitChange n cash accountInyentory Cost Fiow AsSmprions$42$Less inventory replacement$20010050200150$E$00700500200$FIFOLIFOUnitCostLCostTolalS$400$ S$80\mathrm{.}000$S$440520$S$44,00048024,000104,000$S$6084,000256000$$$336,000$CID FEOFORM$2$Specific ID$$320,000$FORM$9$SpectcFORM$11$UnitsSoldSpecic IDS$64,000200$FORM$5$ FORM$6$ FORM$720050050$these totals must agreeS$0$FORM$13$ FORM$1450$$$320000$FORM$10$FORM$12$these totals must agree weh cel D$16$ncomeFIFO$(256,000)$S$64\mathrm{.}000$Unitswith cell B$17$UFOFORM$3$Sokd$DLFO$$320$o$,000$FORMBUFOAverageFORM$4$UnitsCash Elow AnayssEIFO UEOAverageS$320,000$ S$320000$ $$320,000$ S$320,00026\mathrm{.}000)(256\mathrm{.}000)(256\mathrm{.}000)$Sold$$320000$AverageS$050$StatementFIFOS$64000$ S$64\mathrm{.}000$