Finding the Third Proportional to 642,839 and 1,399,969

Step by Step Solution

1. Step 1: Write the proportion equation
   642,839 : 1,399,969 = 1,399,969 : x
2. Step 2: Convert to fraction form
   642,839/1,399,969 = 1,399,969/x
3. Step 3: Cross multiply
   642,839x = 1,399,969 × 1,399,969
4. Step 4: Simplify right side
   642,839x = 1,959,913,200,961
5. Step 5: Solve for x
   x = 1,959,913,200,961/642,839
6. Step 6: Final answer
   x = 3,048,839.91