Finding the Fourth Proportional to 111.18, 153.42 and 71.85

Step by Step Solution

1. Step 1: Write the proportion equation
   111.18 : 153.42 = 71.85 : x
2. Step 2: Convert to fraction form
   111.18/153.42 = 71.85/x
3. Step 3: Cross multiply
   111.18x = 153.42 × 71.85
4. Step 4: Simplify right side
   111.18x = 11,023.23
5. Step 5: Solve for x
   x = 11,023.23/111.18
6. Step 6: Final answer
   x = 99.15