$0\mathrm{.}7$ units$/$hr

a$)$ Sanding is the bottleneck.

b$)$ The bottleneck time is $33\mathrm{.}33$ minutes per unit $($round your response to two decimal places$).$

c$)$ The throughput time of the overall system is $156\mathrm{.}04$ minutes $($round your response to two decimal places$).$

d$)$ If the firm operates $8$ hours per day, $20$ days per month, the monthly capacity of the manufacturing process is units $($enter your response as a whole number$).$