Finding the Fourth Proportional to 111.82, 168.37 and 81.58

Step by Step Solution

1. Step 1: Write the proportion equation
   111.82 : 168.37 = 81.58 : x
2. Step 2: Convert to fraction form
   111.82/168.37 = 81.58/x
3. Step 3: Cross multiply
   111.82x = 168.37 × 81.58
4. Step 4: Simplify right side
   111.82x = 13,735.62
5. Step 5: Solve for x
   x = 13,735.62/111.82
6. Step 6: Final answer
   x = 122.84