Finding the Third Proportional to 309,661.31 and 680,216.91

Step by Step Solution

1. Step 1: Write the proportion equation
   309,661.31 : 680,216.91 = 680,216.91 : x
2. Step 2: Convert to fraction form
   309,661.31/680,216.91 = 680,216.91/x
3. Step 3: Cross multiply
   309,661.31x = 680,216.91 × 680,216.91
4. Step 4: Simplify right side
   309,661.31x = 462,695,039,548.32
5. Step 5: Solve for x
   x = 462,695,039,548.32/309,661.31
6. Step 6: Final answer
   x = 1,494,197.11