Finding the Fourth Proportional to 28.88, 42.72 and 28.72

Step by Step Solution

1. Step 1: Write the proportion equation
   28.88 : 42.72 = 28.72 : x
2. Step 2: Convert to fraction form
   28.88/42.72 = 28.72/x
3. Step 3: Cross multiply
   28.88x = 42.72 × 28.72
4. Step 4: Simplify right side
   28.88x = 1,226.92
5. Step 5: Solve for x
   x = 1,226.92/28.88
6. Step 6: Final answer
   x = 42.48