Finding the Third Proportional to 311,716.50 and 672,078

Step by Step Solution

1. Step 1: Write the proportion equation
   311,716.50 : 672,078 = 672,078 : x
2. Step 2: Convert to fraction form
   311,716.50/672,078 = 672,078/x
3. Step 3: Cross multiply
   311,716.50x = 672,078 × 672,078
4. Step 4: Simplify right side
   311,716.50x = 451,688,838,084
5. Step 5: Solve for x
   x = 451,688,838,084/311,716.50
6. Step 6: Final answer
   x = 1,449,037.31