In order to test the effectiveness of the debate of the candidates for the president, researchers randomly contacted 1000 people on the phone. An attempt was made to contact all 1000 one day before the debate and ask their voting intentions. Only 910 were actually reached by phone; 80 out of the 910 people refused to participate. One day after the debate, 810 of the 910 people were reached and again asked their voting intentions. In addition they were asked if they had seen the debate on television. The before-after change of the viewers and non-viewers were compared to conclude which candidate was more effective in the debate. What kind of experimental design is being used

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.)