Finding the Third Proportional to 321,672 and 687,517.50

Step by Step Solution

1. Step 1: Write the proportion equation
   321,672 : 687,517.50 = 687,517.50 : x
2. Step 2: Convert to fraction form
   321,672/687,517.50 = 687,517.50/x
3. Step 3: Cross multiply
   321,672x = 687,517.50 × 687,517.50
4. Step 4: Simplify right side
   321,672x = 472,680,312,806.25
5. Step 5: Solve for x
   x = 472,680,312,806.25/321,672
6. Step 6: Final answer
   x = 1,469,448.11