Finding the Third Proportional to 128,520.50 and 278,491

Step by Step Solution

1. Step 1: Write the proportion equation
   128,520.50 : 278,491 = 278,491 : x
2. Step 2: Convert to fraction form
   128,520.50/278,491 = 278,491/x
3. Step 3: Cross multiply
   128,520.50x = 278,491 × 278,491
4. Step 4: Simplify right side
   128,520.50x = 77,557,237,081
5. Step 5: Solve for x
   x = 77,557,237,081/128,520.50
6. Step 6: Final answer
   x = 603,461.99