Finding the Fourth Proportional to 111.66, 166.31 and 111.06

Step by Step Solution

1. Step 1: Write the proportion equation
   111.66 : 166.31 = 111.06 : x
2. Step 2: Convert to fraction form
   111.66/166.31 = 111.06/x
3. Step 3: Cross multiply
   111.66x = 166.31 × 111.06
4. Step 4: Simplify right side
   111.66x = 18,470.67
5. Step 5: Solve for x
   x = 18,470.67/111.66
6. Step 6: Final answer
   x = 165.42