Finding the Fourth Proportional to 111.08, 166.57 and 42.61

Step by Step Solution

1. Step 1: Write the proportion equation
   111.08 : 166.57 = 42.61 : x
2. Step 2: Convert to fraction form
   111.08/166.57 = 42.61/x
3. Step 3: Cross multiply
   111.08x = 166.57 × 42.61
4. Step 4: Simplify right side
   111.08x = 7,097.55
5. Step 5: Solve for x
   x = 7,097.55/111.08
6. Step 6: Final answer
   x = 63.90