Finding the Fourth Proportional to 111.53, 168.12 and 104.09

Step by Step Solution

1. Step 1: Write the proportion equation
   111.53 : 168.12 = 104.09 : x
2. Step 2: Convert to fraction form
   111.53/168.12 = 104.09/x
3. Step 3: Cross multiply
   111.53x = 168.12 × 104.09
4. Step 4: Simplify right side
   111.53x = 17,499.61
5. Step 5: Solve for x
   x = 17,499.61/111.53
6. Step 6: Final answer
   x = 156.91