Finding the Third Proportional to 643,853,690 and 1,394,670,404

Step by Step Solution

1. Step 1: Write the proportion equation
   643,853,690 : 1,394,670,404 = 1,394,670,404 : x
2. Step 2: Convert to fraction form
   643,853,690/1,394,670,404 = 1,394,670,404/x
3. Step 3: Cross multiply
   643,853,690x = 1,394,670,404 × 1,394,670,404
4. Step 4: Simplify right side
   643,853,690x = 1,945,105,535,793,523,200
5. Step 5: Solve for x
   x = 1,945,105,535,793,523,200/643,853,690
6. Step 6: Final answer
   x = 3,021,036,558.47