Finding the Fourth Proportional to 105,518.56, 145,615.60 and 57,771.89

Step by Step Solution

1. Step 1: Write the proportion equation
   105,518.56 : 145,615.60 = 57,771.89 : x
2. Step 2: Convert to fraction form
   105,518.56/145,615.60 = 57,771.89/x
3. Step 3: Cross multiply
   105,518.56x = 145,615.60 × 57,771.89
4. Step 4: Simplify right side
   105,518.56x = 8,412,488,425.48
5. Step 5: Solve for x
   x = 8,412,488,425.48/105,518.56
6. Step 6: Final answer
   x = 79,725.20