Finding the Fourth Proportional to 111.13, 166.39 and 72.49

Step by Step Solution

1. Step 1: Write the proportion equation
   111.13 : 166.39 = 72.49 : x
2. Step 2: Convert to fraction form
   111.13/166.39 = 72.49/x
3. Step 3: Cross multiply
   111.13x = 166.39 × 72.49
4. Step 4: Simplify right side
   111.13x = 12,061.61
5. Step 5: Solve for x
   x = 12,061.61/111.13
6. Step 6: Final answer
   x = 108.54