Finding the Fourth Proportional to 111.63, 154.17 and 105.57

Step by Step Solution

1. Step 1: Write the proportion equation
   111.63 : 154.17 = 105.57 : x
2. Step 2: Convert to fraction form
   111.63/154.17 = 105.57/x
3. Step 3: Cross multiply
   111.63x = 154.17 × 105.57
4. Step 4: Simplify right side
   111.63x = 16,275.73
5. Step 5: Solve for x
   x = 16,275.73/111.63
6. Step 6: Final answer
   x = 145.80