Finding the Third Proportional to 639,384 and 938,340

Step by Step Solution

1. Step 1: Write the proportion equation
   639,384 : 938,340 = 938,340 : x
2. Step 2: Convert to fraction form
   639,384/938,340 = 938,340/x
3. Step 3: Cross multiply
   639,384x = 938,340 × 938,340
4. Step 4: Simplify right side
   639,384x = 880,481,955,600
5. Step 5: Solve for x
   x = 880,481,955,600/639,384
6. Step 6: Final answer
   x = 1,377,078.49