Finding the Third Proportional to 396,578 and 819,831.50

Step by Step Solution

1. Step 1: Write the proportion equation
   396,578 : 819,831.50 = 819,831.50 : x
2. Step 2: Convert to fraction form
   396,578/819,831.50 = 819,831.50/x
3. Step 3: Cross multiply
   396,578x = 819,831.50 × 819,831.50
4. Step 4: Simplify right side
   396,578x = 672,123,688,392.25
5. Step 5: Solve for x
   x = 672,123,688,392.25/396,578
6. Step 6: Final answer
   x = 1,694,808.31