Finding the Fourth Proportional to 111.97, 168.09 and 111.77

Step by Step Solution

1. Step 1: Write the proportion equation
   111.97 : 168.09 = 111.77 : x
2. Step 2: Convert to fraction form
   111.97/168.09 = 111.77/x
3. Step 3: Cross multiply
   111.97x = 168.09 × 111.77
4. Step 4: Simplify right side
   111.97x = 18,787.42
5. Step 5: Solve for x
   x = 18,787.42/111.97
6. Step 6: Final answer
   x = 167.79