Finding the Third Proportional to 339,412 and 670,256

Step by Step Solution

1. Step 1: Write the proportion equation
   339,412 : 670,256 = 670,256 : x
2. Step 2: Convert to fraction form
   339,412/670,256 = 670,256/x
3. Step 3: Cross multiply
   339,412x = 670,256 × 670,256
4. Step 4: Simplify right side
   339,412x = 449,243,105,536
5. Step 5: Solve for x
   x = 449,243,105,536/339,412
6. Step 6: Final answer
   x = 1,323,592.29