Finding the Third Proportional to 128,372 and 309,256

Step by Step Solution

1. Step 1: Write the proportion equation
   128,372 : 309,256 = 309,256 : x
2. Step 2: Convert to fraction form
   128,372/309,256 = 309,256/x
3. Step 3: Cross multiply
   128,372x = 309,256 × 309,256
4. Step 4: Simplify right side
   128,372x = 95,639,273,536
5. Step 5: Solve for x
   x = 95,639,273,536/128,372
6. Step 6: Final answer
   x = 745,016.62