Finding the Fourth Proportional to 111.16, 153.56 and 78.35

Step by Step Solution

1. Step 1: Write the proportion equation
   111.16 : 153.56 = 78.35 : x
2. Step 2: Convert to fraction form
   111.16/153.56 = 78.35/x
3. Step 3: Cross multiply
   111.16x = 153.56 × 78.35
4. Step 4: Simplify right side
   111.16x = 12,031.03
5. Step 5: Solve for x
   x = 12,031.03/111.16
6. Step 6: Final answer
   x = 108.24