Finding the Fourth Proportional to 105.82, 158.57 and 76.86

Step by Step Solution

1. Step 1: Write the proportion equation
   105.82 : 158.57 = 76.86 : x
2. Step 2: Convert to fraction form
   105.82/158.57 = 76.86/x
3. Step 3: Cross multiply
   105.82x = 158.57 × 76.86
4. Step 4: Simplify right side
   105.82x = 12,187.59
5. Step 5: Solve for x
   x = 12,187.59/105.82
6. Step 6: Final answer
   x = 115.18