Finding the Fourth Proportional to 111.68, 153.98 and 80.56

Step by Step Solution

1. Step 1: Write the proportion equation
   111.68 : 153.98 = 80.56 : x
2. Step 2: Convert to fraction form
   111.68/153.98 = 80.56/x
3. Step 3: Cross multiply
   111.68x = 153.98 × 80.56
4. Step 4: Simplify right side
   111.68x = 12,404.63
5. Step 5: Solve for x
   x = 12,404.63/111.68
6. Step 6: Final answer
   x = 111.07