Saud and Bros maintain periodic inventory system. Additional information $-$ Total sales revenue for April$-$June: $\backslash (\backslash$$ $17,920\backslash ),$ units $560$ @ $\backslash (\backslash$$ $32\backslash )$ Required Using the weighted$-$average $($average$-$cost$)$ method: $1.$ Compute the weighted$-$average cost per unit for the period. $2.$ Determine units sold during the period. $3.$ Calculate cost of goods sold $($COGS$)$ in $($a$)$ units and $($b$)$ dollars. $4.$ Calculate ending inventory in $($a$)$ units and $($b$)$ dollars.