Based on Gatalla and Oearce (1974). Northwest Airlines has determined that it needs the number of…

Based on Gatalla and Oearce (1974). Northwest Airlines has
determined that it needs the number of ticket agents during each hour of the day,
as listed in the file P04_75.xlsx. Workers work nine-hour shifts, one hour of
which is for lunch. The lunch hour can be either the fourth or fifth hour of
their shift. What is the minimum number of workers needed by Northwest?