Finding the Fourth Proportional to 81,105.12, 121,676.40 and 28,514.88

Step by Step Solution

1. Step 1: Write the proportion equation
   81,105.12 : 121,676.40 = 28,514.88 : x
2. Step 2: Convert to fraction form
   81,105.12/121,676.40 = 28,514.88/x
3. Step 3: Cross multiply
   81,105.12x = 121,676.40 × 28,514.88
4. Step 4: Simplify right side
   81,105.12x = 3,469,587,944.83
5. Step 5: Solve for x
   x = 3,469,587,944.83/81,105.12
6. Step 6: Final answer
   x = 42,778.90