Finding the Third Proportional to 313,099.50 and 685,275

Step by Step Solution

1. Step 1: Write the proportion equation
   313,099.50 : 685,275 = 685,275 : x
2. Step 2: Convert to fraction form
   313,099.50/685,275 = 685,275/x
3. Step 3: Cross multiply
   313,099.50x = 685,275 × 685,275
4. Step 4: Simplify right side
   313,099.50x = 469,601,825,625
5. Step 5: Solve for x
   x = 469,601,825,625/313,099.50
6. Step 6: Final answer
   x = 1,499,848.53