Finding the Fourth Proportional to 19.72, 29.39 and 19.15

Step by Step Solution

1. Step 1: Write the proportion equation
   19.72 : 29.39 = 19.15 : x
2. Step 2: Convert to fraction form
   19.72/29.39 = 19.15/x
3. Step 3: Cross multiply
   19.72x = 29.39 × 19.15
4. Step 4: Simplify right side
   19.72x = 562.82
5. Step 5: Solve for x
   x = 562.82/19.72
6. Step 6: Final answer
   x = 28.54