Early Morning Delivery Service guarantees delivery of small packages by 10:30 a.m. Of course, some of the packages are not delivered by 10:30 a.m. For a sample of 200 packages delivered each of the last 15 working days, the following numbers of packages were delivered after the deadline: 9, 14, 2, 13, 9, 5, 9, 3, 4, 3, 4, 3, 3, 8, and 4.
a. Determine the mean proportion of packages delivered after 10:30 a.m.
b. Determine the control limits for the proportion of packages delivered after 10:30 a.m. Were any of the sampled days out of control?
c. If 10 packages out of 200 in the sample were delivered after 10:30 a.m. today, is this sample within the control limits?