Finding the Third Proportional to 442,478 and 680,505

Step by Step Solution

1. Step 1: Write the proportion equation
   442,478 : 680,505 = 680,505 : x
2. Step 2: Convert to fraction form
   442,478/680,505 = 680,505/x
3. Step 3: Cross multiply
   442,478x = 680,505 × 680,505
4. Step 4: Simplify right side
   442,478x = 463,087,055,025
5. Step 5: Solve for x
   x = 463,087,055,025/442,478
6. Step 6: Final answer
   x = 1,046,576.45