Finding the Fourth Proportional to 111.09, 166.55 and 42.67

Step by Step Solution

1. Step 1: Write the proportion equation
   111.09 : 166.55 = 42.67 : x
2. Step 2: Convert to fraction form
   111.09/166.55 = 42.67/x
3. Step 3: Cross multiply
   111.09x = 166.55 × 42.67
4. Step 4: Simplify right side
   111.09x = 7,106.78
5. Step 5: Solve for x
   x = 7,106.78/111.09
6. Step 6: Final answer
   x = 63.97