Finding the Fourth Proportional to 81,123.12, 112,059.48 and 61,131.12

Step by Step Solution

1. Step 1: Write the proportion equation
   81,123.12 : 112,059.48 = 61,131.12 : x
2. Step 2: Convert to fraction form
   81,123.12/112,059.48 = 61,131.12/x
3. Step 3: Cross multiply
   81,123.12x = 112,059.48 × 61,131.12
4. Step 4: Simplify right side
   81,123.12x = 6,850,321,519.02
5. Step 5: Solve for x
   x = 6,850,321,519.02/81,123.12
6. Step 6: Final answer
   x = 84,443.52