Finding the Fourth Proportional to 111.45, 166.35 and 108.72

Step by Step Solution

1. Step 1: Write the proportion equation
   111.45 : 166.35 = 108.72 : x
2. Step 2: Convert to fraction form
   111.45/166.35 = 108.72/x
3. Step 3: Cross multiply
   111.45x = 166.35 × 108.72
4. Step 4: Simplify right side
   111.45x = 18,085.57
5. Step 5: Solve for x
   x = 18,085.57/111.45
6. Step 6: Final answer
   x = 162.28