Finding the Fourth Proportional to 105,725.13, 145,907.33 and 57,978.49

Step by Step Solution

1. Step 1: Write the proportion equation
   105,725.13 : 145,907.33 = 57,978.49 : x
2. Step 2: Convert to fraction form
   105,725.13/145,907.33 = 57,978.49/x
3. Step 3: Cross multiply
   105,725.13x = 145,907.33 × 57,978.49
4. Step 4: Simplify right side
   105,725.13x = 8,459,486,702.61
5. Step 5: Solve for x
   x = 8,459,486,702.61/105,725.13
6. Step 6: Final answer
   x = 80,013.96