Finding the Third Proportional to 424,440 and 642,144.38

Step by Step Solution

1. Step 1: Write the proportion equation
   424,440 : 642,144.38 = 642,144.38 : x
2. Step 2: Convert to fraction form
   424,440/642,144.38 = 642,144.38/x
3. Step 3: Cross multiply
   424,440x = 642,144.38 × 642,144.38
4. Step 4: Simplify right side
   424,440x = 412,349,398,344.14
5. Step 5: Solve for x
   x = 412,349,398,344.14/424,440
6. Step 6: Final answer
   x = 971,513.99