Finding the Fourth Proportional to 111.34, 153.68 and 86.82

Step by Step Solution

1. Step 1: Write the proportion equation
   111.34 : 153.68 = 86.82 : x
2. Step 2: Convert to fraction form
   111.34/153.68 = 86.82/x
3. Step 3: Cross multiply
   111.34x = 153.68 × 86.82
4. Step 4: Simplify right side
   111.34x = 13,342.50
5. Step 5: Solve for x
   x = 13,342.50/111.34
6. Step 6: Final answer
   x = 119.84