Finding the Fourth Proportional to 111.69, 154.18 and 86.73

Step by Step Solution

1. Step 1: Write the proportion equation
   111.69 : 154.18 = 86.73 : x
2. Step 2: Convert to fraction form
   111.69/154.18 = 86.73/x
3. Step 3: Cross multiply
   111.69x = 154.18 × 86.73
4. Step 4: Simplify right side
   111.69x = 13,372.03
5. Step 5: Solve for x
   x = 13,372.03/111.69
6. Step 6: Final answer
   x = 119.73