Finding the Fourth Proportional to 111.31, 167.68 and 109.89

Step by Step Solution

1. Step 1: Write the proportion equation
   111.31 : 167.68 = 109.89 : x
2. Step 2: Convert to fraction form
   111.31/167.68 = 109.89/x
3. Step 3: Cross multiply
   111.31x = 167.68 × 109.89
4. Step 4: Simplify right side
   111.31x = 18,426.18
5. Step 5: Solve for x
   x = 18,426.18/111.31
6. Step 6: Final answer
   x = 165.54