Finding the Fourth Proportional to 111.06, 166.51 and 42.55

Step by Step Solution

1. Step 1: Write the proportion equation
   111.06 : 166.51 = 42.55 : x
2. Step 2: Convert to fraction form
   111.06/166.51 = 42.55/x
3. Step 3: Cross multiply
   111.06x = 166.51 × 42.55
4. Step 4: Simplify right side
   111.06x = 7,085.14
5. Step 5: Solve for x
   x = 7,085.14/111.06
6. Step 6: Final answer
   x = 63.79