Finding the Fourth Proportional to 309,755.72, 427,593.38 and 209,289.80

Step by Step Solution

1. Step 1: Write the proportion equation
   309,755.72 : 427,593.38 = 209,289.80 : x
2. Step 2: Convert to fraction form
   309,755.72/427,593.38 = 209,289.80/x
3. Step 3: Cross multiply
   309,755.72x = 427,593.38 × 209,289.80
4. Step 4: Simplify right side
   309,755.72x = 89,490,932,981.52
5. Step 5: Solve for x
   x = 89,490,932,981.52/309,755.72
6. Step 6: Final answer
   x = 288,908.09