Finding the Third Proportional to 128,402.72 and 274,612.78

Step by Step Solution

1. Step 1: Write the proportion equation
   128,402.72 : 274,612.78 = 274,612.78 : x
2. Step 2: Convert to fraction form
   128,402.72/274,612.78 = 274,612.78/x
3. Step 3: Cross multiply
   128,402.72x = 274,612.78 × 274,612.78
4. Step 4: Simplify right side
   128,402.72x = 75,412,179,625.86
5. Step 5: Solve for x
   x = 75,412,179,625.86/128,402.72
6. Step 6: Final answer
   x = 587,309.84