Finding the Fourth Proportional to 30.72, 42.42 and 29.18

Step by Step Solution

1. Step 1: Write the proportion equation
   30.72 : 42.42 = 29.18 : x
2. Step 2: Convert to fraction form
   30.72/42.42 = 29.18/x
3. Step 3: Cross multiply
   30.72x = 42.42 × 29.18
4. Step 4: Simplify right side
   30.72x = 1,237.82
5. Step 5: Solve for x
   x = 1,237.82/30.72
6. Step 6: Final answer
   x = 40.29