Finding the Fourth Proportional to 111.16, 165.83 and 109.72

Step by Step Solution

1. Step 1: Write the proportion equation
   111.16 : 165.83 = 109.72 : x
2. Step 2: Convert to fraction form
   111.16/165.83 = 109.72/x
3. Step 3: Cross multiply
   111.16x = 165.83 × 109.72
4. Step 4: Simplify right side
   111.16x = 18,194.87
5. Step 5: Solve for x
   x = 18,194.87/111.16
6. Step 6: Final answer
   x = 163.68