Finding the Fourth Proportional to 111.07, 166.49 and 42.55

Step by Step Solution

1. Step 1: Write the proportion equation
   111.07 : 166.49 = 42.55 : x
2. Step 2: Convert to fraction form
   111.07/166.49 = 42.55/x
3. Step 3: Cross multiply
   111.07x = 166.49 × 42.55
4. Step 4: Simplify right side
   111.07x = 7,084.15
5. Step 5: Solve for x
   x = 7,084.15/111.07
6. Step 6: Final answer
   x = 63.78