Finding the Fourth Proportional to 111.25, 153.48 and 78.55

Step by Step Solution

1. Step 1: Write the proportion equation
   111.25 : 153.48 = 78.55 : x
2. Step 2: Convert to fraction form
   111.25/153.48 = 78.55/x
3. Step 3: Cross multiply
   111.25x = 153.48 × 78.55
4. Step 4: Simplify right side
   111.25x = 12,055.85
5. Step 5: Solve for x
   x = 12,055.85/111.25
6. Step 6: Final answer
   x = 108.37