Finding the Fourth Proportional to 111.72, 166.63 and 108.30

Step by Step Solution

1. Step 1: Write the proportion equation
   111.72 : 166.63 = 108.30 : x
2. Step 2: Convert to fraction form
   111.72/166.63 = 108.30/x
3. Step 3: Cross multiply
   111.72x = 166.63 × 108.30
4. Step 4: Simplify right side
   111.72x = 18,046.30
5. Step 5: Solve for x
   x = 18,046.30/111.72
6. Step 6: Final answer
   x = 161.54