Finding the Fourth Proportional to 111.17, 154.31 and 106.72

Step by Step Solution

1. Step 1: Write the proportion equation
   111.17 : 154.31 = 106.72 : x
2. Step 2: Convert to fraction form
   111.17/154.31 = 106.72/x
3. Step 3: Cross multiply
   111.17x = 154.31 × 106.72
4. Step 4: Simplify right side
   111.17x = 16,467.04
5. Step 5: Solve for x
   x = 16,467.04/111.17
6. Step 6: Final answer
   x = 148.12