Finding the Third Proportional to 321,240 and 685,229.50

Step by Step Solution

1. Step 1: Write the proportion equation
   321,240 : 685,229.50 = 685,229.50 : x
2. Step 2: Convert to fraction form
   321,240/685,229.50 = 685,229.50/x
3. Step 3: Cross multiply
   321,240x = 685,229.50 × 685,229.50
4. Step 4: Simplify right side
   321,240x = 469,539,467,670.25
5. Step 5: Solve for x
   x = 469,539,467,670.25/321,240
6. Step 6: Final answer
   x = 1,461,646.95