Finding the Fourth Proportional to 111.14, 166.65 and 42.61

Step by Step Solution

1. Step 1: Write the proportion equation
   111.14 : 166.65 = 42.61 : x
2. Step 2: Convert to fraction form
   111.14/166.65 = 42.61/x
3. Step 3: Cross multiply
   111.14x = 166.65 × 42.61
4. Step 4: Simplify right side
   111.14x = 7,099.91
5. Step 5: Solve for x
   x = 7,099.91/111.14
6. Step 6: Final answer
   x = 63.89