Finding the Fourth Proportional to 105.91, 158.59 and 89.71

Step by Step Solution

1. Step 1: Write the proportion equation
   105.91 : 158.59 = 89.71 : x
2. Step 2: Convert to fraction form
   105.91/158.59 = 89.71/x
3. Step 3: Cross multiply
   105.91x = 158.59 × 89.71
4. Step 4: Simplify right side
   105.91x = 14,227.11
5. Step 5: Solve for x
   x = 14,227.11/105.91
6. Step 6: Final answer
   x = 134.33