Finding the Fourth Proportional to 111.30, 153.69 and 81.96

Step by Step Solution

1. Step 1: Write the proportion equation
   111.30 : 153.69 = 81.96 : x
2. Step 2: Convert to fraction form
   111.30/153.69 = 81.96/x
3. Step 3: Cross multiply
   111.30x = 153.69 × 81.96
4. Step 4: Simplify right side
   111.30x = 12,596.43
5. Step 5: Solve for x
   x = 12,596.43/111.30
6. Step 6: Final answer
   x = 113.18