Finding the Fourth Proportional to 42.30, 63.36 and 28.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42.30 : 63.36 = 28.72 : x
2. Step 2: Convert to fraction form
   42.30/63.36 = 28.72/x
3. Step 3: Cross multiply
   42.30x = 63.36 × 28.72
4. Step 4: Simplify right side
   42.30x = 1,819.70
5. Step 5: Solve for x
   x = 1,819.70/42.30
6. Step 6: Final answer
   x = 43.02