Finding the Third Proportional to 421,501.50 and 642,744

Step by Step Solution

1. Step 1: Write the proportion equation
   421,501.50 : 642,744 = 642,744 : x
2. Step 2: Convert to fraction form
   421,501.50/642,744 = 642,744/x
3. Step 3: Cross multiply
   421,501.50x = 642,744 × 642,744
4. Step 4: Simplify right side
   421,501.50x = 413,119,849,536
5. Step 5: Solve for x
   x = 413,119,849,536/421,501.50
6. Step 6: Final answer
   x = 980,114.78