Finding the Third Proportional to 639,188 and 1,398,644

Step by Step Solution

1. Step 1: Write the proportion equation
   639,188 : 1,398,644 = 1,398,644 : x
2. Step 2: Convert to fraction form
   639,188/1,398,644 = 1,398,644/x
3. Step 3: Cross multiply
   639,188x = 1,398,644 × 1,398,644
4. Step 4: Simplify right side
   639,188x = 1,956,205,038,736
5. Step 5: Solve for x
   x = 1,956,205,038,736/639,188
6. Step 6: Final answer
   x = 3,060,453.32