Finding the Fourth Proportional to 85,961.14, 129,139.39 and 61,061.78

Step by Step Solution

1. Step 1: Write the proportion equation
   85,961.14 : 129,139.39 = 61,061.78 : x
2. Step 2: Convert to fraction form
   85,961.14/129,139.39 = 61,061.78/x
3. Step 3: Cross multiply
   85,961.14x = 129,139.39 × 61,061.78
4. Step 4: Simplify right side
   85,961.14x = 7,885,481,021.51
5. Step 5: Solve for x
   x = 7,885,481,021.51/85,961.14
6. Step 6: Final answer
   x = 91,733.09