Answer:
3 Sales people
Explanation:
The calculation of total cost per shift is shown below:-
1st sales 2nd sales 3rd sales 4th sales
person person person person
Average Waiting
Time 10 minutes 6 minutes 3 minutes 2 minutes
Total waiting
Cost $720 $432 $216 $144
(72 × $1 × 10) (72 × $1 × 6) (72 × $1 × 3) (72 × $1 × 2)
Add: Total labor
Cost 80 $160 $240 $320
($80 × 1) ($80 × 2) ($80 × 3) ($80 × 4)
Total cost $800 $592 $456 $464
Thus, 3 servers have the lowest cost, so that the overall cost per change with 3 Sales people is chosen.