Finding the Third Proportional to 321,670 and 687,513.50

Step by Step Solution

1. Step 1: Write the proportion equation
   321,670 : 687,513.50 = 687,513.50 : x
2. Step 2: Convert to fraction form
   321,670/687,513.50 = 687,513.50/x
3. Step 3: Cross multiply
   321,670x = 687,513.50 × 687,513.50
4. Step 4: Simplify right side
   321,670x = 472,674,812,682.25
5. Step 5: Solve for x
   x = 472,674,812,682.25/321,670
6. Step 6: Final answer
   x = 1,469,440.15