Finding the Fourth Proportional to 111.28, 153.42 and 78.52

Step by Step Solution

1. Step 1: Write the proportion equation
   111.28 : 153.42 = 78.52 : x
2. Step 2: Convert to fraction form
   111.28/153.42 = 78.52/x
3. Step 3: Cross multiply
   111.28x = 153.42 × 78.52
4. Step 4: Simplify right side
   111.28x = 12,046.54
5. Step 5: Solve for x
   x = 12,046.54/111.28
6. Step 6: Final answer
   x = 108.25