Sandy Shores, Inc., a manufacturer of men's flip$-$flops, uses the high low method to estimate cost behaviors. In its current manufacturing operations, three different cost types are incurred: A$,$ B$,$ and C$.$ Per unit costs for each cost type at two different activity levels are as follows:

$\backslash$table$[[,$A$,$B$,$C$],[5,000$ pairs of flip$-$flops,$$4\mathrm{.}00,$$$9\mathrm{.}00,$$$4\mathrm{.}00$