Finding the Fourth Proportional to 111.96, 154.56 and 108.72

Step by Step Solution

1. Step 1: Write the proportion equation
   111.96 : 154.56 = 108.72 : x
2. Step 2: Convert to fraction form
   111.96/154.56 = 108.72/x
3. Step 3: Cross multiply
   111.96x = 154.56 × 108.72
4. Step 4: Simplify right side
   111.96x = 16,803.76
5. Step 5: Solve for x
   x = 16,803.76/111.96
6. Step 6: Final answer
   x = 150.09