Finding the Fourth Proportional to 85,589.31, 128,115 and 58,778.31

Step by Step Solution

1. Step 1: Write the proportion equation
   85,589.31 : 128,115 = 58,778.31 : x
2. Step 2: Convert to fraction form
   85,589.31/128,115 = 58,778.31/x
3. Step 3: Cross multiply
   85,589.31x = 128,115 × 58,778.31
4. Step 4: Simplify right side
   85,589.31x = 7,530,383,185.65
5. Step 5: Solve for x
   x = 7,530,383,185.65/85,589.31
6. Step 6: Final answer
   x = 87,982.75