Finding the Third Proportional to 399,616 and 856,231

Step by Step Solution

1. Step 1: Write the proportion equation
   399,616 : 856,231 = 856,231 : x
2. Step 2: Convert to fraction form
   399,616/856,231 = 856,231/x
3. Step 3: Cross multiply
   399,616x = 856,231 × 856,231
4. Step 4: Simplify right side
   399,616x = 733,131,525,361
5. Step 5: Solve for x
   x = 733,131,525,361/399,616
6. Step 6: Final answer
   x = 1,834,590.02