Finding the Third Proportional to 205,643 and 280,153.50

Step by Step Solution

1. Step 1: Write the proportion equation
   205,643 : 280,153.50 = 280,153.50 : x
2. Step 2: Convert to fraction form
   205,643/280,153.50 = 280,153.50/x
3. Step 3: Cross multiply
   205,643x = 280,153.50 × 280,153.50
4. Step 4: Simplify right side
   205,643x = 78,485,983,562.25
5. Step 5: Solve for x
   x = 78,485,983,562.25/205,643
6. Step 6: Final answer
   x = 381,661.34