Finding the Third Proportional to 642,688 and 1,399,808

Step by Step Solution

1. Step 1: Write the proportion equation
   642,688 : 1,399,808 = 1,399,808 : x
2. Step 2: Convert to fraction form
   642,688/1,399,808 = 1,399,808/x
3. Step 3: Cross multiply
   642,688x = 1,399,808 × 1,399,808
4. Step 4: Simplify right side
   642,688x = 1,959,462,436,864
5. Step 5: Solve for x
   x = 1,959,462,436,864/642,688
6. Step 6: Final answer
   x = 3,048,854.87