How many Spanish$-$speaking and English$-$speaking operators do the hospital need to staff the call center during each $2-$hour shift of the day so that the total labor cost is minimum? Provide an integer number since half a human operator makes no sense. $(15$ marks$)$

Question $2$

Suppose the average number of calls per hour increases to $50($from $35)$ for the shift $5$:$00-7$:$00$ p$.$m$.$ What is the new optimal staffing plan? How many Spanish$-$speaking and English$-$speaking operators are required during each $2-$hour shift of the day?