The anterior cruciate ligament (ACL) is one of the ligaments that help stabilize the knee. Surgery is often
recommended if the ACL is completely torn, and recovery time from the surgery can be lengthy. A medical
center developed a new surgical procedure designed to reduce the average recovery time from the surgery. To
test the effectiveness of the new procedure, a study was conducted in which 210 patients needing surgery to
repair a torn ACL were randomly assigned to receive either the standard procedure or the new procedure.
(a) Based on the design of the study, would a statistically significant result allow the medical center to conclude
that the new procedure causes a reduction in recovery time compared to the standard procedure, for patients
similar to those in the study? Explain your answer.

Acaterer knows he will need 60, 50, 80, 40 and 50 dinner napkins on five successive evenings. he can purchase new napkins initially at 25 cents each, after which he can have dirty napkins laundered by a fast one-day laundry service (i.e., dirty napkins given at the end of the day will be ready for use the following day) at 15 cents each, or by a slow two-day service at 8 cents each or both. the caterer wants to know how many napkins he should purchase initially and how many dirty napkins should be laundered by fast and slow service on each of the days in order to minimize his total costs. formulate the caterer’s problem as a linear program as follows (you must state any assumptions you make): a. define all variables clearly. how many are there? b. write out the constraints that must be satisfied, briefly explaining each. (do not simplify.) write out the objective function to be minimized. (do not simplify.)