Finding the Third Proportional to 321,384.50 and 667,680

Step by Step Solution

1. Step 1: Write the proportion equation
   321,384.50 : 667,680 = 667,680 : x
2. Step 2: Convert to fraction form
   321,384.50/667,680 = 667,680/x
3. Step 3: Cross multiply
   321,384.50x = 667,680 × 667,680
4. Step 4: Simplify right side
   321,384.50x = 445,796,582,400
5. Step 5: Solve for x
   x = 445,796,582,400/321,384.50
6. Step 6: Final answer
   x = 1,387,112.89