Finding the Third Proportional to 309,037.50 and 641,760

Step by Step Solution

1. Step 1: Write the proportion equation
   309,037.50 : 641,760 = 641,760 : x
2. Step 2: Convert to fraction form
   309,037.50/641,760 = 641,760/x
3. Step 3: Cross multiply
   309,037.50x = 641,760 × 641,760
4. Step 4: Simplify right side
   309,037.50x = 411,855,897,600
5. Step 5: Solve for x
   x = 411,855,897,600/309,037.50
6. Step 6: Final answer
   x = 1,332,705.25