Finding the Fourth Proportional to 86,105.30, 128,927.55 and 54,770.90

Step by Step Solution

1. Step 1: Write the proportion equation
   86,105.30 : 128,927.55 = 54,770.90 : x
2. Step 2: Convert to fraction form
   86,105.30/128,927.55 = 54,770.90/x
3. Step 3: Cross multiply
   86,105.30x = 128,927.55 × 54,770.90
4. Step 4: Simplify right side
   86,105.30x = 7,061,477,948.30
5. Step 5: Solve for x
   x = 7,061,477,948.30/86,105.30
6. Step 6: Final answer
   x = 82,009.79