Finding the Third Proportional to 298,210.50 and 639,009

Step by Step Solution

1. Step 1: Write the proportion equation
   298,210.50 : 639,009 = 639,009 : x
2. Step 2: Convert to fraction form
   298,210.50/639,009 = 639,009/x
3. Step 3: Cross multiply
   298,210.50x = 639,009 × 639,009
4. Step 4: Simplify right side
   298,210.50x = 408,332,502,081
5. Step 5: Solve for x
   x = 408,332,502,081/298,210.50
6. Step 6: Final answer
   x = 1,369,276.07