Finding the Third Proportional to 123,498 and 256,686

Step by Step Solution

1. Step 1: Write the proportion equation
   123,498 : 256,686 = 256,686 : x
2. Step 2: Convert to fraction form
   123,498/256,686 = 256,686/x
3. Step 3: Cross multiply
   123,498x = 256,686 × 256,686
4. Step 4: Simplify right side
   123,498x = 65,887,702,596
5. Step 5: Solve for x
   x = 65,887,702,596/123,498
6. Step 6: Final answer
   x = 533,512.30