Finding the Third Proportional to 315,561 and 688,945.50

Step by Step Solution

1. Step 1: Write the proportion equation
   315,561 : 688,945.50 = 688,945.50 : x
2. Step 2: Convert to fraction form
   315,561/688,945.50 = 688,945.50/x
3. Step 3: Cross multiply
   315,561x = 688,945.50 × 688,945.50
4. Step 4: Simplify right side
   315,561x = 474,645,901,970.25
5. Step 5: Solve for x
   x = 474,645,901,970.25/315,561
6. Step 6: Final answer
   x = 1,504,133.60