Finding the Third Proportional to 128,815.50 and 280,512

Step by Step Solution

1. Step 1: Write the proportion equation
   128,815.50 : 280,512 = 280,512 : x
2. Step 2: Convert to fraction form
   128,815.50/280,512 = 280,512/x
3. Step 3: Cross multiply
   128,815.50x = 280,512 × 280,512
4. Step 4: Simplify right side
   128,815.50x = 78,686,982,144
5. Step 5: Solve for x
   x = 78,686,982,144/128,815.50
6. Step 6: Final answer
   x = 610,850.26