Actual lengths of stay at a hospital's emergency department in 2009 are shown in the following table (rounded to the nearest hour). Length of stay is the total of wait and service times. Some longer...

Extracted text: Actual lengths of stay at a hospital's emergency department in 2009 are shown in the following table (rounded to the nearest hour). Length of stay is the total of wait and service times. Some longer stays are also approximated as 15 hours in this table. Hours Count Percent 19 3.80 51 10.20 86 17.20 4 102 20.40 87 17.40 62 12.40 7 40 8.00 8. 18 3.60 14 2.80 10 11 2.20 15 10 2.00 Calculate the probability mass function of the wait time for service. 2. 3.