Finding the Third Proportional to 271,617 and 399,105

Step by Step Solution

1. Step 1: Write the proportion equation
   271,617 : 399,105 = 399,105 : x
2. Step 2: Convert to fraction form
   271,617/399,105 = 399,105/x
3. Step 3: Cross multiply
   271,617x = 399,105 × 399,105
4. Step 4: Simplify right side
   271,617x = 159,284,801,025
5. Step 5: Solve for x
   x = 159,284,801,025/271,617
6. Step 6: Final answer
   x = 586,431.63