Finding the Fourth Proportional to 28.27, 42.42 and 19.72

Step by Step Solution

1. Step 1: Write the proportion equation
   28.27 : 42.42 = 19.72 : x
2. Step 2: Convert to fraction form
   28.27/42.42 = 19.72/x
3. Step 3: Cross multiply
   28.27x = 42.42 × 19.72
4. Step 4: Simplify right side
   28.27x = 836.42
5. Step 5: Solve for x
   x = 836.42/28.27
6. Step 6: Final answer
   x = 29.59