Finding the Third Proportional to 399,066 and 861,436

Step by Step Solution

1. Step 1: Write the proportion equation
   399,066 : 861,436 = 861,436 : x
2. Step 2: Convert to fraction form
   399,066/861,436 = 861,436/x
3. Step 3: Cross multiply
   399,066x = 861,436 × 861,436
4. Step 4: Simplify right side
   399,066x = 742,071,982,096
5. Step 5: Solve for x
   x = 742,071,982,096/399,066
6. Step 6: Final answer
   x = 1,859,521.94