Finding the Third Proportional to 428,828 and 647,610

Step by Step Solution

1. Step 1: Write the proportion equation
   428,828 : 647,610 = 647,610 : x
2. Step 2: Convert to fraction form
   428,828/647,610 = 647,610/x
3. Step 3: Cross multiply
   428,828x = 647,610 × 647,610
4. Step 4: Simplify right side
   428,828x = 419,398,712,100
5. Step 5: Solve for x
   x = 419,398,712,100/428,828
6. Step 6: Final answer
   x = 978,011.49