Finding the Fourth Proportional to 111.98, 168.08 and 89.10

Step by Step Solution

1. Step 1: Write the proportion equation
   111.98 : 168.08 = 89.10 : x
2. Step 2: Convert to fraction form
   111.98/168.08 = 89.10/x
3. Step 3: Cross multiply
   111.98x = 168.08 × 89.10
4. Step 4: Simplify right side
   111.98x = 14,975.48
5. Step 5: Solve for x
   x = 14,975.48/111.98
6. Step 6: Final answer
   x = 133.73