Finding the Third Proportional to 615,990 and 921,469

Step by Step Solution

1. Step 1: Write the proportion equation
   615,990 : 921,469 = 921,469 : x
2. Step 2: Convert to fraction form
   615,990/921,469 = 921,469/x
3. Step 3: Cross multiply
   615,990x = 921,469 × 921,469
4. Step 4: Simplify right side
   615,990x = 849,105,117,961
5. Step 5: Solve for x
   x = 849,105,117,961/615,990
6. Step 6: Final answer
   x = 1,378,439.78