Finding the Fourth Proportional to 865,933,796.55, 1,298,900,669.72 and 399,457,205.09

Step by Step Solution

1. Step 1: Write the proportion equation
   865,933,796.55 : 1,298,900,669.72 = 399,457,205.09 : x
2. Step 2: Convert to fraction form
   865,933,796.55/1,298,900,669.72 = 399,457,205.09/x
3. Step 3: Cross multiply
   865,933,796.55x = 1,298,900,669.72 × 399,457,205.09
4. Step 4: Simplify right side
   865,933,796.55x = 518,855,231,215,880,384
5. Step 5: Solve for x
   x = 518,855,231,215,880,384/865,933,796.55
6. Step 6: Final answer
   x = 599,185,796.05