Finding the Third Proportional to 643,853,686 and 1,394,670,397.50

Step by Step Solution

1. Step 1: Write the proportion equation
   643,853,686 : 1,394,670,397.50 = 1,394,670,397.50 : x
2. Step 2: Convert to fraction form
   643,853,686/1,394,670,397.50 = 1,394,670,397.50/x
3. Step 3: Cross multiply
   643,853,686x = 1,394,670,397.50 × 1,394,670,397.50
4. Step 4: Simplify right side
   643,853,686x = 1,945,105,517,662,808,064
5. Step 5: Solve for x
   x = 1,945,105,517,662,808,064/643,853,686
6. Step 6: Final answer
   x = 3,021,036,549.08