Finding the Fourth Proportional to 111.07, 153.30 and 78.34

Step by Step Solution

1. Step 1: Write the proportion equation
   111.07 : 153.30 = 78.34 : x
2. Step 2: Convert to fraction form
   111.07/153.30 = 78.34/x
3. Step 3: Cross multiply
   111.07x = 153.30 × 78.34
4. Step 4: Simplify right side
   111.07x = 12,009.52
5. Step 5: Solve for x
   x = 12,009.52/111.07
6. Step 6: Final answer
   x = 108.13