Finding the Fourth Proportional to 111.75, 166.69 and 109.89

Step by Step Solution

1. Step 1: Write the proportion equation
   111.75 : 166.69 = 109.89 : x
2. Step 2: Convert to fraction form
   111.75/166.69 = 109.89/x
3. Step 3: Cross multiply
   111.75x = 166.69 × 109.89
4. Step 4: Simplify right side
   111.75x = 18,317.70
5. Step 5: Solve for x
   x = 18,317.70/111.75
6. Step 6: Final answer
   x = 163.92