Finding the Third Proportional to 639,359 and 1,399,123

Step by Step Solution

1. Step 1: Write the proportion equation
   639,359 : 1,399,123 = 1,399,123 : x
2. Step 2: Convert to fraction form
   639,359/1,399,123 = 1,399,123/x
3. Step 3: Cross multiply
   639,359x = 1,399,123 × 1,399,123
4. Step 4: Simplify right side
   639,359x = 1,957,545,169,129
5. Step 5: Solve for x
   x = 1,957,545,169,129/639,359
6. Step 6: Final answer
   x = 3,061,730.84