Finding the Third Proportional to 315,622 and 686,540

Step by Step Solution

1. Step 1: Write the proportion equation
   315,622 : 686,540 = 686,540 : x
2. Step 2: Convert to fraction form
   315,622/686,540 = 686,540/x
3. Step 3: Cross multiply
   315,622x = 686,540 × 686,540
4. Step 4: Simplify right side
   315,622x = 471,337,171,600
5. Step 5: Solve for x
   x = 471,337,171,600/315,622
6. Step 6: Final answer
   x = 1,493,359.69