Finding the Fourth Proportional to 105.79, 158.84 and 86.33

Step by Step Solution

1. Step 1: Write the proportion equation
   105.79 : 158.84 = 86.33 : x
2. Step 2: Convert to fraction form
   105.79/158.84 = 86.33/x
3. Step 3: Cross multiply
   105.79x = 158.84 × 86.33
4. Step 4: Simplify right side
   105.79x = 13,711.86
5. Step 5: Solve for x
   x = 13,711.86/105.79
6. Step 6: Final answer
   x = 129.62