Finding the Fourth Proportional to 105.12, 144.76 and 72.32

Step by Step Solution

1. Step 1: Write the proportion equation
   105.12 : 144.76 = 72.32 : x
2. Step 2: Convert to fraction form
   105.12/144.76 = 72.32/x
3. Step 3: Cross multiply
   105.12x = 144.76 × 72.32
4. Step 4: Simplify right side
   105.12x = 10,469.04
5. Step 5: Solve for x
   x = 10,469.04/105.12
6. Step 6: Final answer
   x = 99.59