Finding the Fourth Proportional to 111.18, 153.12 and 89.28

Step by Step Solution

1. Step 1: Write the proportion equation
   111.18 : 153.12 = 89.28 : x
2. Step 2: Convert to fraction form
   111.18/153.12 = 89.28/x
3. Step 3: Cross multiply
   111.18x = 153.12 × 89.28
4. Step 4: Simplify right side
   111.18x = 13,670.55
5. Step 5: Solve for x
   x = 13,670.55/111.18
6. Step 6: Final answer
   x = 122.96