Finding the Third Proportional to 313,870.50 and 686,425.50

Step by Step Solution

1. Step 1: Write the proportion equation
   313,870.50 : 686,425.50 = 686,425.50 : x
2. Step 2: Convert to fraction form
   313,870.50/686,425.50 = 686,425.50/x
3. Step 3: Cross multiply
   313,870.50x = 686,425.50 × 686,425.50
4. Step 4: Simplify right side
   313,870.50x = 471,179,967,050.25
5. Step 5: Solve for x
   x = 471,179,967,050.25/313,870.50
6. Step 6: Final answer
   x = 1,501,192.27