Finding the Fourth Proportional to 111.29, 153.39 and 80.12

Step by Step Solution

1. Step 1: Write the proportion equation
   111.29 : 153.39 = 80.12 : x
2. Step 2: Convert to fraction form
   111.29/153.39 = 80.12/x
3. Step 3: Cross multiply
   111.29x = 153.39 × 80.12
4. Step 4: Simplify right side
   111.29x = 12,289.61
5. Step 5: Solve for x
   x = 12,289.61/111.29
6. Step 6: Final answer
   x = 110.43