Finding the Third Proportional to 311,078 and 642,892

Step by Step Solution

1. Step 1: Write the proportion equation
   311,078 : 642,892 = 642,892 : x
2. Step 2: Convert to fraction form
   311,078/642,892 = 642,892/x
3. Step 3: Cross multiply
   311,078x = 642,892 × 642,892
4. Step 4: Simplify right side
   311,078x = 413,310,123,664
5. Step 5: Solve for x
   x = 413,310,123,664/311,078
6. Step 6: Final answer
   x = 1,328,638.23