Finding the Fourth Proportional to 42.29, 63.42 and 21.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42.29 : 63.42 = 21.72 : x
2. Step 2: Convert to fraction form
   42.29/63.42 = 21.72/x
3. Step 3: Cross multiply
   42.29x = 63.42 × 21.72
4. Step 4: Simplify right side
   42.29x = 1,377.17
5. Step 5: Solve for x
   x = 1,377.17/42.29
6. Step 6: Final answer
   x = 32.56