Finding the Third Proportional to 261,061 and 415,401

Step by Step Solution

1. Step 1: Write the proportion equation
   261,061 : 415,401 = 415,401 : x
2. Step 2: Convert to fraction form
   261,061/415,401 = 415,401/x
3. Step 3: Cross multiply
   261,061x = 415,401 × 415,401
4. Step 4: Simplify right side
   261,061x = 172,557,990,801
5. Step 5: Solve for x
   x = 172,557,990,801/261,061
6. Step 6: Final answer
   x = 660,987.24