Finding the Third Proportional to 642,690 and 1,399,812

Step by Step Solution

1. Step 1: Write the proportion equation
   642,690 : 1,399,812 = 1,399,812 : x
2. Step 2: Convert to fraction form
   642,690/1,399,812 = 1,399,812/x
3. Step 3: Cross multiply
   642,690x = 1,399,812 × 1,399,812
4. Step 4: Simplify right side
   642,690x = 1,959,473,635,344
5. Step 5: Solve for x
   x = 1,959,473,635,344/642,690
6. Step 6: Final answer
   x = 3,048,862.80