Finding the Third Proportional to 640.83 and 774.56

Step by Step Solution

1. Step 1: Write the proportion equation
   640.83 : 774.56 = 774.56 : x
2. Step 2: Convert to fraction form
   640.83/774.56 = 774.56/x
3. Step 3: Cross multiply
   640.83x = 774.56 × 774.56
4. Step 4: Simplify right side
   640.83x = 599,947.07
5. Step 5: Solve for x
   x = 599,947.07/640.83
6. Step 6: Final answer
   x = 936.21