Finding the Fourth Proportional to 85,510.40, 128,419.20 and 82,745.60

Step by Step Solution

1. Step 1: Write the proportion equation
   85,510.40 : 128,419.20 = 82,745.60 : x
2. Step 2: Convert to fraction form
   85,510.40/128,419.20 = 82,745.60/x
3. Step 3: Cross multiply
   85,510.40x = 128,419.20 × 82,745.60
4. Step 4: Simplify right side
   85,510.40x = 10,626,123,755.52
5. Step 5: Solve for x
   x = 10,626,123,755.52/85,510.40
6. Step 6: Final answer
   x = 124,267.03