Finding the Fourth Proportional to 257,196.89, 355,024.88 and 209,367.20

Step by Step Solution

1. Step 1: Write the proportion equation
   257,196.89 : 355,024.88 = 209,367.20 : x
2. Step 2: Convert to fraction form
   257,196.89/355,024.88 = 209,367.20/x
3. Step 3: Cross multiply
   257,196.89x = 355,024.88 × 209,367.20
4. Step 4: Simplify right side
   257,196.89x = 74,330,562,233.98
5. Step 5: Solve for x
   x = 74,330,562,233.98/257,196.89
6. Step 6: Final answer
   x = 289,002.58