A dietitian in a hospital is to arrange a special diet composed of three basic foods. The diet is to include exactly 140 units of​ calcium, 100 units of​ iron, and 140 units of vitamin A.

 A dietitian in a hospital is to arrange a special diet composed of three basic foods. The diet is to include exactly 140 units of​ calcium, 100 units of​ iron, and 140 units of vitamin A. The number of units per ounce of each special ingredient for each of the foods is indicated in the table. Construct a mathematical model to complete parts​ (A) through​ (C) below. Use​ Gauss-Jordan elimination to solve the model and then interpret the solution.

​(A) How many ounces of each food must be used to meet the diet​ requirements?

 

 

 

 

 

 

 

 

 

 

 

 

Two sociologists have grant money to study school busing in a particular city. They wish to conduct an opinion survey using 691telephone contacts and 471house contacts.

 Two sociologists have grant money to study school busing in a particular city. They wish to conduct an opinion survey using 691telephone contacts and 471house contacts. Survey company A has personnel to do 37 telephone and 13 house contacts per​ hour; survey company B can handle 28 telephone and 20
 house contacts per hour. How many hours should be scheduled for each firm to produce exactly the number of contacts​ needed?