HP 10bii+ Margin/Markup bug

[ijabbott]

Even though margin/markup conversions are slightly suboptimal on the HP 10bii+ (requiring a dummy value for cost or price and solving for the other), at least we can gloat on the fact that this is much better than the TI BAII Plus, which has separate worksheets for "profit" (cost / price / margin) and "percentage change" (old (cost) / new (price) / %change (markup)), with no interaction between the two.