Finding the Third Proportional to 393,709.50 and 813,665.25

Step by Step Solution

1. Step 1: Write the proportion equation
   393,709.50 : 813,665.25 = 813,665.25 : x
2. Step 2: Convert to fraction form
   393,709.50/813,665.25 = 813,665.25/x
3. Step 3: Cross multiply
   393,709.50x = 813,665.25 × 813,665.25
4. Step 4: Simplify right side
   393,709.50x = 662,051,139,057.56
5. Step 5: Solve for x
   x = 662,051,139,057.56/393,709.50
6. Step 6: Final answer
   x = 1,681,572.68