Finding the Fourth Proportional to 105.12, 144.85 and 86.83

Step by Step Solution

1. Step 1: Write the proportion equation
   105.12 : 144.85 = 86.83 : x
2. Step 2: Convert to fraction form
   105.12/144.85 = 86.83/x
3. Step 3: Cross multiply
   105.12x = 144.85 × 86.83
4. Step 4: Simplify right side
   105.12x = 12,577.33
5. Step 5: Solve for x
   x = 12,577.33/105.12
6. Step 6: Final answer
   x = 119.65