Finding the Fourth Proportional to 105.12, 144.72 and 103.50

Step by Step Solution

1. Step 1: Write the proportion equation
   105.12 : 144.72 = 103.50 : x
2. Step 2: Convert to fraction form
   105.12/144.72 = 103.50/x
3. Step 3: Cross multiply
   105.12x = 144.72 × 103.50
4. Step 4: Simplify right side
   105.12x = 14,978.52
5. Step 5: Solve for x
   x = 14,978.52/105.12
6. Step 6: Final answer
   x = 142.49