Finding the Fourth Proportional to 111.69, 154.02 and 80.80

Step by Step Solution

1. Step 1: Write the proportion equation
   111.69 : 154.02 = 80.80 : x
2. Step 2: Convert to fraction form
   111.69/154.02 = 80.80/x
3. Step 3: Cross multiply
   111.69x = 154.02 × 80.80
4. Step 4: Simplify right side
   111.69x = 12,444.82
5. Step 5: Solve for x
   x = 12,444.82/111.69
6. Step 6: Final answer
   x = 111.42