Finding the Third Proportional to 309,361.78 and 671,211.56

Step by Step Solution

1. Step 1: Write the proportion equation
   309,361.78 : 671,211.56 = 671,211.56 : x
2. Step 2: Convert to fraction form
   309,361.78/671,211.56 = 671,211.56/x
3. Step 3: Cross multiply
   309,361.78x = 671,211.56 × 671,211.56
4. Step 4: Simplify right side
   309,361.78x = 450,524,961,633.69
5. Step 5: Solve for x
   x = 450,524,961,633.69/309,361.78
6. Step 6: Final answer
   x = 1,456,304.52