Finding the Third Proportional to 638,608.50 and 1,399,689

Step by Step Solution

1. Step 1: Write the proportion equation
   638,608.50 : 1,399,689 = 1,399,689 : x
2. Step 2: Convert to fraction form
   638,608.50/1,399,689 = 1,399,689/x
3. Step 3: Cross multiply
   638,608.50x = 1,399,689 × 1,399,689
4. Step 4: Simplify right side
   638,608.50x = 1,959,129,296,721
5. Step 5: Solve for x
   x = 1,959,129,296,721/638,608.50
6. Step 6: Final answer
   x = 3,067,809.62