Finding the Fourth Proportional to 105,479.72, 145,561.48 and 57,081.61

Step by Step Solution

1. Step 1: Write the proportion equation
   105,479.72 : 145,561.48 = 57,081.61 : x
2. Step 2: Convert to fraction form
   105,479.72/145,561.48 = 57,081.61/x
3. Step 3: Cross multiply
   105,479.72x = 145,561.48 × 57,081.61
4. Step 4: Simplify right side
   105,479.72x = 8,308,883,632.38
5. Step 5: Solve for x
   x = 8,308,883,632.38/105,479.72
6. Step 6: Final answer
   x = 78,772.33