Finding the Fourth Proportional to 318,171.72, 439,078.42 and 172,978.92

Step by Step Solution

1. Step 1: Write the proportion equation
   318,171.72 : 439,078.42 = 172,978.92 : x
2. Step 2: Convert to fraction form
   318,171.72/439,078.42 = 172,978.92/x
3. Step 3: Cross multiply
   318,171.72x = 439,078.42 × 172,978.92
4. Step 4: Simplify right side
   318,171.72x = 75,951,310,886.91
5. Step 5: Solve for x
   x = 75,951,310,886.91/318,171.72
6. Step 6: Final answer
   x = 238,711.70