$1.$ The process yield is $\_\_\_\_\_.$ To produce $300$ good units at the end of Step $4,$ the operations manager needs to start $\_\_\_\_\_$ units at Step $1.$

$-62\%,$ start $323$ units

$-62\%,$ start $484$ units

$-80\%,$ start $375$ units

$-86\%,$ start $348$ units

$2.$ The operations manager recalls reading about a company reduced waste in its process by $25\%$ by increasing yield at one step in its process by $15\%($from $70\%$ to $80\mathrm{.}5\%).$ If managers improve the yield of Step $3$ and Step $4$ by $10\%,$ how many fewer units will need to be started at Step $1$ to produce $300$ units at the end of Step $4?$

$-84$ fewer units

$-400$ fewer units

$-161$ fewer units

$-56$ fewer units