Finding the Third Proportional to 389,661 and 809,938.50

Step by Step Solution

1. Step 1: Write the proportion equation
   389,661 : 809,938.50 = 809,938.50 : x
2. Step 2: Convert to fraction form
   389,661/809,938.50 = 809,938.50/x
3. Step 3: Cross multiply
   389,661x = 809,938.50 × 809,938.50
4. Step 4: Simplify right side
   389,661x = 656,000,373,782.25
5. Step 5: Solve for x
   x = 656,000,373,782.25/389,661
6. Step 6: Final answer
   x = 1,683,515.60