Finding the Fourth Proportional to 111.91, 168.02 and 89.18

Step by Step Solution

1. Step 1: Write the proportion equation
   111.91 : 168.02 = 89.18 : x
2. Step 2: Convert to fraction form
   111.91/168.02 = 89.18/x
3. Step 3: Cross multiply
   111.91x = 168.02 × 89.18
4. Step 4: Simplify right side
   111.91x = 14,984.02
5. Step 5: Solve for x
   x = 14,984.02/111.91
6. Step 6: Final answer
   x = 133.89