Finding the Fourth Proportional to 111.67, 167.37 and 81.37

Step by Step Solution

1. Step 1: Write the proportion equation
   111.67 : 167.37 = 81.37 : x
2. Step 2: Convert to fraction form
   111.67/167.37 = 81.37/x
3. Step 3: Cross multiply
   111.67x = 167.37 × 81.37
4. Step 4: Simplify right side
   111.67x = 13,618.90
5. Step 5: Solve for x
   x = 13,618.90/111.67
6. Step 6: Final answer
   x = 121.96