Finding the Fourth Proportional to 256,139.86, 384,204.38 and 85,373.94

Step by Step Solution

1. Step 1: Write the proportion equation
   256,139.86 : 384,204.38 = 85,373.94 : x
2. Step 2: Convert to fraction form
   256,139.86/384,204.38 = 85,373.94/x
3. Step 3: Cross multiply
   256,139.86x = 384,204.38 × 85,373.94
4. Step 4: Simplify right side
   256,139.86x = 32,801,041,685.86
5. Step 5: Solve for x
   x = 32,801,041,685.86/256,139.86
6. Step 6: Final answer
   x = 128,059.11