Finding the Third Proportional to 678,739 and 1,340,345

Step by Step Solution

1. Step 1: Write the proportion equation
   678,739 : 1,340,345 = 1,340,345 : x
2. Step 2: Convert to fraction form
   678,739/1,340,345 = 1,340,345/x
3. Step 3: Cross multiply
   678,739x = 1,340,345 × 1,340,345
4. Step 4: Simplify right side
   678,739x = 1,796,524,719,025
5. Step 5: Solve for x
   x = 1,796,524,719,025/678,739
6. Step 6: Final answer
   x = 2,646,856.48