Finding the Fourth Proportional to 639,196.88, 959,223 and 265,219.88

Step by Step Solution

1. Step 1: Write the proportion equation
   639,196.88 : 959,223 = 265,219.88 : x
2. Step 2: Convert to fraction form
   639,196.88/959,223 = 265,219.88/x
3. Step 3: Cross multiply
   639,196.88x = 959,223 × 265,219.88
4. Step 4: Simplify right side
   639,196.88x = 254,405,008,953.24
5. Step 5: Solve for x
   x = 254,405,008,953.24/639,196.88
6. Step 6: Final answer
   x = 398,007.28