Finding the Fourth Proportional to 111.13, 166.55 and 72.63

Step by Step Solution

1. Step 1: Write the proportion equation
   111.13 : 166.55 = 72.63 : x
2. Step 2: Convert to fraction form
   111.13/166.55 = 72.63/x
3. Step 3: Cross multiply
   111.13x = 166.55 × 72.63
4. Step 4: Simplify right side
   111.13x = 12,096.71
5. Step 5: Solve for x
   x = 12,096.71/111.13
6. Step 6: Final answer
   x = 108.85