Finding the Third Proportional to 398,388 and 863,155.50

Step by Step Solution

1. Step 1: Write the proportion equation
   398,388 : 863,155.50 = 863,155.50 : x
2. Step 2: Convert to fraction form
   398,388/863,155.50 = 863,155.50/x
3. Step 3: Cross multiply
   398,388x = 863,155.50 × 863,155.50
4. Step 4: Simplify right side
   398,388x = 745,037,417,180.25
5. Step 5: Solve for x
   x = 745,037,417,180.25/398,388
6. Step 6: Final answer
   x = 1,870,130.17