Finding the Third Proportional to 381,978.50 and 809,491

Step by Step Solution

1. Step 1: Write the proportion equation
   381,978.50 : 809,491 = 809,491 : x
2. Step 2: Convert to fraction form
   381,978.50/809,491 = 809,491/x
3. Step 3: Cross multiply
   381,978.50x = 809,491 × 809,491
4. Step 4: Simplify right side
   381,978.50x = 655,275,679,081
5. Step 5: Solve for x
   x = 655,275,679,081/381,978.50
6. Step 6: Final answer
   x = 1,715,477.91