Finding the Third Proportional to 321,666 and 687,505.50

Step by Step Solution

1. Step 1: Write the proportion equation
   321,666 : 687,505.50 = 687,505.50 : x
2. Step 2: Convert to fraction form
   321,666/687,505.50 = 687,505.50/x
3. Step 3: Cross multiply
   321,666x = 687,505.50 × 687,505.50
4. Step 4: Simplify right side
   321,666x = 472,663,812,530.25
5. Step 5: Solve for x
   x = 472,663,812,530.25/321,666
6. Step 6: Final answer
   x = 1,469,424.22