Finding the Third Proportional to 309,660 and 680,215.50

Step by Step Solution

1. Step 1: Write the proportion equation
   309,660 : 680,215.50 = 680,215.50 : x
2. Step 2: Convert to fraction form
   309,660/680,215.50 = 680,215.50/x
3. Step 3: Cross multiply
   309,660x = 680,215.50 × 680,215.50
4. Step 4: Simplify right side
   309,660x = 462,693,126,440.25
5. Step 5: Solve for x
   x = 462,693,126,440.25/309,660
6. Step 6: Final answer
   x = 1,494,197.27