Finding the Third Proportional to 120,039 and 257,870

Step by Step Solution

1. Step 1: Write the proportion equation
   120,039 : 257,870 = 257,870 : x
2. Step 2: Convert to fraction form
   120,039/257,870 = 257,870/x
3. Step 3: Cross multiply
   120,039x = 257,870 × 257,870
4. Step 4: Simplify right side
   120,039x = 66,496,936,900
5. Step 5: Solve for x
   x = 66,496,936,900/120,039
6. Step 6: Final answer
   x = 553,961.10