Finding the Third Proportional to 443,869 and 686,519

Step by Step Solution

1. Step 1: Write the proportion equation
   443,869 : 686,519 = 686,519 : x
2. Step 2: Convert to fraction form
   443,869/686,519 = 686,519/x
3. Step 3: Cross multiply
   443,869x = 686,519 × 686,519
4. Step 4: Simplify right side
   443,869x = 471,308,337,361
5. Step 5: Solve for x
   x = 471,308,337,361/443,869
6. Step 6: Final answer
   x = 1,061,818.55