Finding the Third Proportional to 518,009 and 800,021.50

Step by Step Solution

1. Step 1: Write the proportion equation
   518,009 : 800,021.50 = 800,021.50 : x
2. Step 2: Convert to fraction form
   518,009/800,021.50 = 800,021.50/x
3. Step 3: Cross multiply
   518,009x = 800,021.50 × 800,021.50
4. Step 4: Simplify right side
   518,009x = 640,034,400,462.25
5. Step 5: Solve for x
   x = 640,034,400,462.25/518,009
6. Step 6: Final answer
   x = 1,235,566.18