Given the following retail figures for March and an initial markup of $48\mathrm{.}5\%,$ calculate the open$-$to$-$buy for March $15$ th in $($a$)$ retail dollars and $($b$)$ cost dollars. a$.$ Net Sales: $$21,300$ b$.$ Inventory on March $1$: $$68,225$ c$.$ Inventory on March $31$: $$71,990$ d$.$ Planned March Markdowns: $$1,200$ e$.$ Merchandise on Order as of $3/15$: $$9,800$