Finding the Fourth Proportional to 156,978.81, 235,468.37 and 57,139.83

Step by Step Solution

1. Step 1: Write the proportion equation
   156,978.81 : 235,468.37 = 57,139.83 : x
2. Step 2: Convert to fraction form
   156,978.81/235,468.37 = 57,139.83/x
3. Step 3: Cross multiply
   156,978.81x = 235,468.37 × 57,139.83
4. Step 4: Simplify right side
   156,978.81x = 13,454,622,453.62
5. Step 5: Solve for x
   x = 13,454,622,453.62/156,978.81
6. Step 6: Final answer
   x = 85,709.80