In example $2\mathrm{.}1,$ we used a cost to produce, $P,$ of $$4\mathrm{.}00.$ If we were able to reduce this to $$3\mathrm{.}55$ through greater attention in the design, and if the cost to improve the design $($in NRE$)$ is $$35,000,$ how many units must we sell to recover the increased design cost? Calculate for both the $=50\%$ and $=75\%$ cases. What conclusions can you draw from this?

$D=$ design and development expense $$200,000$