Finding the Fourth Proportional to 105,568.28, 145,679.42 and 57,820.61

Step by Step Solution

1. Step 1: Write the proportion equation
   105,568.28 : 145,679.42 = 57,820.61 : x
2. Step 2: Convert to fraction form
   105,568.28/145,679.42 = 57,820.61/x
3. Step 3: Cross multiply
   105,568.28x = 145,679.42 × 57,820.61
4. Step 4: Simplify right side
   105,568.28x = 8,423,272,345.00
5. Step 5: Solve for x
   x = 8,423,272,345.00/105,568.28
6. Step 6: Final answer
   x = 79,789.80