Finding the Fourth Proportional to 111.55, 166.09 and 104.87

Step by Step Solution

1. Step 1: Write the proportion equation
   111.55 : 166.09 = 104.87 : x
2. Step 2: Convert to fraction form
   111.55/166.09 = 104.87/x
3. Step 3: Cross multiply
   111.55x = 166.09 × 104.87
4. Step 4: Simplify right side
   111.55x = 17,417.86
5. Step 5: Solve for x
   x = 17,417.86/111.55
6. Step 6: Final answer
   x = 156.14