Finding the Fourth Proportional to 111.59, 167.61 and 86.03

Step by Step Solution

1. Step 1: Write the proportion equation
   111.59 : 167.61 = 86.03 : x
2. Step 2: Convert to fraction form
   111.59/167.61 = 86.03/x
3. Step 3: Cross multiply
   111.59x = 167.61 × 86.03
4. Step 4: Simplify right side
   111.59x = 14,419.49
5. Step 5: Solve for x
   x = 14,419.49/111.59
6. Step 6: Final answer
   x = 129.22