Finding the Fourth Proportional to 88,939.80, 133,081.65 and 81,066.60

Step by Step Solution

1. Step 1: Write the proportion equation
   88,939.80 : 133,081.65 = 81,066.60 : x
2. Step 2: Convert to fraction form
   88,939.80/133,081.65 = 81,066.60/x
3. Step 3: Cross multiply
   88,939.80x = 133,081.65 × 81,066.60
4. Step 4: Simplify right side
   88,939.80x = 10,788,476,887.89
5. Step 5: Solve for x
   x = 10,788,476,887.89/88,939.80
6. Step 6: Final answer
   x = 121,300.89