Finding the Fourth Proportional to 65,236.80, 89,826.60 and 57,124.05

Step by Step Solution

1. Step 1: Write the proportion equation
   65,236.80 : 89,826.60 = 57,124.05 : x
2. Step 2: Convert to fraction form
   65,236.80/89,826.60 = 57,124.05/x
3. Step 3: Cross multiply
   65,236.80x = 89,826.60 × 57,124.05
4. Step 4: Simplify right side
   65,236.80x = 5,131,259,189.73
5. Step 5: Solve for x
   x = 5,131,259,189.73/65,236.80
6. Step 6: Final answer
   x = 78,655.90