Finding the Fourth Proportional to 339,936.72, 509,832.18 and 140,205.30

Step by Step Solution

1. Step 1: Write the proportion equation
   339,936.72 : 509,832.18 = 140,205.30 : x
2. Step 2: Convert to fraction form
   339,936.72/509,832.18 = 140,205.30/x
3. Step 3: Cross multiply
   339,936.72x = 509,832.18 × 140,205.30
4. Step 4: Simplify right side
   339,936.72x = 71,481,173,746.55
5. Step 5: Solve for x
   x = 71,481,173,746.55/339,936.72
6. Step 6: Final answer
   x = 210,277.88